We have now come to the end of our transmission. But before the screen starts to crackle and fuzzy black and white dots appear, there is time to tell you that there will be live text commentary at around 02:00 BST on Thursday of Andy Murray's quarter-final tussle with Novak Djokovic. Bye for now.
- Roger Federer wins 6-4 6-3 6-2 vs Roberto Bautista Agut
- Tomas Berdych defeats Dominic Thiem 6-1 6-2 6-4
- Gael Monfils beats Grigor Dimitrov 7-5 7-6 (8-6) 7-5
- Marin Cilic beats Gilles Simon 5-7 7-6 (7-3) 6-4 3-6 6-3
- Peng Shuai defeats Belinda Bencic 6-2 6-1 to reach semi-finals
- *denotes next to serve
It's quarter-finals Wednesday. Here is how the day should unfold on Arthur Ashe Stadium:
Victoria Azarenka v Ekaterina Makarova (not before 17:30 BST)
Stan Wawrinka v Kei Nishikori
Serena Williams v Flavia Pennetta (not before 00:00 BST)
Novak Djokovic v Andy Murray
Ahead of Andy Murray's quarter-final match with Novak Djokovic, his coach Amelie Mauresmo has been speaking to BBC Sport's tennis correspondent Russell Fuller.
On Murray's vocalvictory over Jo-Wilfried Tsonga, she said: "I haven't really made up my mind on this yet. I think he's old enough now to know what's good for him, how he should behave on the court, what brings him energy, and what maybe is taking him down a little bit sometimes.
"I also want to trust him in a way that he should know by now how to pace himself sometimes, and how to express himself sometimes, because I think it's not black or white. It's not going to be either saying nothing or completely going crazy on the court. I think he has to be in the middle somewhere."
Earlier, Gael Monfils had caused a bit of an upset bybeating seventh seed Grigor Dimitrov 7-5 7-6 (8-6) 7-5.
"The Bulgarian had been expected to set up a first Grand Slam clash with Federer but was outplayed by, for the most part, an unusually consistent Monfils," says BBC Sport's Piers Newbery.
"I think he's one of the most exciting and entertaining opponents out there," says Federer of his quarter-final opponent Gael Monfils. The Swiss, who now equals Pete Sampras and Bill Tilden on 71 US Open singles victories, will play the Frenchman on Thursday.
"It was difficult and we definitely had to adjust to the wind and I'm always happy when I get through those matches," says Federer. "He was tough and I'm happy I was able to control that match."
A double fault from the 17th seed allows Fedeer to level at 30-30 but an uncharacteristic error from Federer, a backhand over the baseline, has Bautista Agut ahead once again.
Federer's response? He simply blows at his fingernails as if he's drying nail polish and proceeds to cook up another winning volley. Deuce. The second seed squanders one match point but sees off his opponent at the second time of asking. A backhand into the tape and that is it. Game over. Federer marches into another Grand Slam quarter-final.
Unforced errors creeping into Federer's game, but the Swiss yells "come on" as he produces a down-the-line winner for 30-30. The Swiss moving his opponent this way and that until the Spaniard clubs his forehand into the tape. Federer has eased off the accelerator, perhaps conserving some fuel for his next road trip now that this particular journey is nearing the end.
A hold to 15 for Bautista Agut and the 26-year-old performing stoically against his more illustrious opponent.
Sixth-seed Czech Tomas Berdych raced to a straight sets 6-1 6-2 6-4 victory over Dominic Thiem in one hour and 38 minutes.
Not the best birthday present for the unseeded Austrian - who turns 21 today. But 2014 has seen his ranking improve dramatically from 139th to 45th - making him the youngest player inside the ATOP top 50.
Berdych will meet Marin Cilic in the quarter-final.
Deuce. Advantage. Deuce. Federer's concentration has dipped. Break point Bautista Agut - a clean forehand winner from the Spaniard, punishing Federer's poor approach play. The Spaniard never convincing when in a position to see off Federer. The 17th seed more like a bumbling second in command rather than a ruthless killer. Federer not at his best, but his volleying in windy conditions is impressive and a backhand winner sees him through.
It is around this time that the predator often catches his prey. Federer has toyed with Bautista Agut, given him plenty of warning that he is circling and is ready to pounce. Bautista Agut, caught in a trap and unable to break free, must defend two break points but he tamely nets a backhand to give his blood-thirsty opponent the game.
At 0-30, a glimpse at why Bautista Agut has won two titles this year. But, then, in the following two points Federer illustrates why he has won 17 Grand Slam titles, hauling himself to 30-30. The Swiss is clinical around the barrier- a backhand volley his coup de grace (and his 31st winner at the net in this match).
Bautista Agut races to a 40-0 lead and although Federer bites back it is, ultimately, a trouble-free hold for the Spaniard.
Blimey. Two break points Bautista Agut. Daylight for the Spaniard, but he is soon made to realise that it was a trick of the light. There's a long, dark tunnel ahead of him. An unreturnable first serve from Federer takes the game to deuce.
Hang on, the Spaniard could have Federer in a pickle... Federer's forehand clips the net, the Swiss advances to the tape, Bautista Agut simply has to whack the ball across the net and Federer will be stranded... Ah, but the Spaniard fails with the attempted passing shot and Federer wriggles free.
Federer's father was seen on camera chuckling to himself as he watched his son serve with aplomb in the previous game and he's probably still smiling now. Today is a good day to be a Federer. Only the one error from Federer's sublime racquet - an overclubbed crosscourt forehand - otherwise it all goes his way. Bautista Agut optimistic with the hot dog, presenting Federer with two set points - and the Spaniard nets a volley to bring the set to a predictable conclusion.
The Federer serve has been a tad unpredictable in this match, but in this game the second seed's serve is as reliable as his country's clocks. A sixth ace. A comfortable hold. A foregone conclusion?
BBC Sport at Flushing Meadows
"I'm telling you, this is the best I've seen Roger move in years." John McEnroe, commentating on ESPN, is not alone in thinking that five-time champion Federer is gliding around the court as in days of yore, i.e. the mid-2000s.
Bautista Agut is rooted at the baseline, grunting and groaning as he is, once again, forced to deuce. Big hitting from the Spaniard, though, forcing Federer to overcook a forehand, and he scrambles free.
A double fault from Federer. A 0-30 lead for Bautista Agut. But the Spaniard looks terrified as he crouches down to face another Federer serve. It's as if he knows a couple of heavy punches are going to come his way, and so they do. Federer clinical at the net. 30-30. But the second seed double faults - his fourth of the match - gifting Bautista Agut a break point. From defence to attack, Federer has time to stand by the tape and ping away an overhead for deuce. No more drama to talk of here.
Bautista Agut in trouble once more, but the 26-year-old saves a break point and it is Federer who is mumbling at the baseline after allowing his opponent to progress to advantage. Federer lets this one slip. "Alright, have this one on me," he says, returning to his chair to plan his crowning move.
Federer will soon be back at base, changing nappies and singing nursery rhymes to his children (although it might be beyond their bedtime. I have no idea. I'm just filling space). A hold to love for the five-time champion. If this were a football match it'd be a testimonial. As pleasant as it is to watch, it is lacking in intensity.
For all the grit in Bautista Agut's guts, there's a sense of inevitability about how this match will end. Federer collecting break points like the rest of us collect two pence coins. Two break points in this game and the Spaniard surrenders with a careless double fault.
Impeccable serving from Federer who quickly levels. Turbo-charged serving from both players at the beginning of this second set.
I suppose if the gremlins are going to play havoc then it's best they do it at the start of a set. During the time I reboot, Bautista Agut shows no signs of being rattled by losing that first set. A comfortable opening game, with the one missed lob the only blot.
BBC Sport at Flushing Meadows
The crowd on Ashe might like to see a real contest here but that could extend their night considerably, with the smart money on Caroline Wozniacki and Sara Errani going fairly long in the final match. Federer continues to look sharp, although winning just 42% of points behind his second serve made him a little vulnerable. The good news is the temperature has plummeted to 32C.
It was only a few minutes ago that Bautista Agut was staring into the headlights with no means of escape but the Spaniard fights back from 30-0 to 30-30 and seeds of doubt are being sowed. Will Federer throw this set away? Oh. Don't be silly. Two aces - rat-a-tat-tat - answers that question.
Federer sprinting from tramline to tramline, stooping to his shoelaces to whack a dipping forehand towards the other side of the net, but the revived Bautista Agut responds with a cool volley to move within a point of a hold. Untroubled and unfazed the 17th seed holds firm. Can Federer serve out this set?
The crowd beginning to root for the underdog, cheering for the Spaniard as Federer, unable to kill off Bautista Agut with tame smashes, concedes three break points. The second seed saves two, but fine returning from the Spaniard forces Federer to shoot long and the game is gone gone gone.
The Federer backhand misfiring - it would have been a lovely cover drive had he been playing with willow and cork. Bautista Agut proceeds to 40-30, but Federer, making regular visits to the net, soon overhauls the Spaniard. But he wastes a break point and Bautista Agut clinches his second game of the match with a cushion-soft drop shot.
Bautista Agut's resistance is made of rice paper. Federer closing in on the first set with a comfortable hold to 15 and this match is progressing as the bookies had predicted.
It is the five-time champion who sneaks to a 15-30 lead, and Bautista Agut's first serve is failing him. The Spaniard drags himself level and comes out on top of a baseline battle - the Federer backhand drifting long - but the advantage is soon wiped out and to deuce we go.
A break point comes Federer's way, Bautista Agut going long once more, but Federer hits a wild return to give his opponent hope. Brilliant defending from Federer and the crowd admiringly applaud as he finishes off a testy rally with a thunderous volley. Second break point comes and goes.
Foot fault by Bautista Augt - the backfoot over the centre line - presents Federer with a third break point. Federer currently as ruthless as a hibernating dormouse. What can he do with the fourth break point? Oh, a beautiful rally! Federer made to scamper on his heels towards the baseline, then the Swiss scoots towards the tape - superb from both players before Federer drills a volley beyond Bautista Agut. Federer marches on.
Federer gliding around the court. What a beguiling sight it is. His cat-like reflexes at the net - a backhand volley followed by a sweetly-struck forehand volley - sees off the Spaniard and consolidates the second seed's advantage.
Federer punishing Bautista Agut's second serves and he's keeping his opponent on his toes by varying play nicely, shooting from the baseline then switching to the net. A heavy-duty overhead from Federer has one spectator nodding in approval. The Spaniard seems to have made Federer angry (insert Incredible Hulk quote if you wish)
Two break points Federer. First serve into the tape... second serve hits the target, but the Spaniard crumbles under pressure, overcooking the forehand.
At 15-15, Federer skips towards the tape - Bautista Agut retrieves one punchy volley after another until the Swiss outwits his opponent with an irretrievable volley at an acute angle. A mixed bag from the second seed - a double fault followed by an ace for a 40-30 score. The Spaniard intent on proving he belongs on such a stage. Big hitting from Federer from the baseline though secures him two quick points, and the game.
Baustista Agut in his Wimbledon whites. Federer in a coal black outfit. A monochrome delight on either end of the court.
Razor-sharp serving from the Spaniard, finishing with a confident 126mph boomer down the 'T' which leaves Federer swinging at fresh air. A hold to 15. Nerves? Nah.
So, how is Roberto Bautista Agut going to achieve the shock of the tournament and beat Roger Federer? Does the Spaniard have a chance? Why not lob us a tweet with your thoughts, using the hashtag #bbctennis
Bautista Agut has not faced a seeded player during his smooth progress to the fourth round, dropping only two sets in what is the furthest he has travelled in any Grand Slam. But playing Federer - who has dropped just one set in this tournament - on a court where the Swiss has won six titles is a significant step up for the Spaniard.
The players have finished their warm-up, by the way, so we should be under way soon.
BBC Sport at Flushing Meadows
It's been another thumpingly hot and humid day in New York, and the temperature is still a woozy 33C as we head into the evening session. The overflowing food courts are finally emptying and the escalators and walkways around Ashe awash with slightly light-headed spectators. It's been so hot that even Federer has been seen to sweat at times. It will be a major surprise if Bautista Agut can extend him to two shirts tonight.