|US Open 2015|
|Venue: Flushing Meadows, New York Dates: 31 August-13 September|
|Coverage: Online radio commentary of Heather Watson, plus live radio and text commentary on every Andy Murray match and selected others.|
Serena Williams and Rafael Nadal lived up to their billing with victories in the first of this year's US Open night sessions.
Top seed Williams needed just 30 minutes to begin her bid for a first calendar Grand Slam as Vitalia Diatchenko retired at 6-0 2-0 down.
Nadal, seeded eighth, saw off 18-year-old Borna Coric 6-3 6-2 4-6 6-4.
World number one Novak Djokovic went through, but fourth seed Kei Nishikori was beaten.
The Japanese player, last year's runner-up, lost 6-4 3-6 4-6 7-6 (8-6) 6-4 to Frenchman Benoit Paire.
"It's always very sad to lose in the first round, but I think he was playing good tennis so I don't think I played bad," Nishikori said.
Djokovic swept past Brazil's Joao Souza 6-1 6-1 6-1 to reach round two, and Nadal showed glimpses of his best form in beating Croatia's Coric.
The Spaniard, 29, dominated the first two sets and then saw off a resurgent Coric in the fourth with a rasping forehand to earn the decisive break.
"I think I started playing well," Nadal said. "The first two sets was a very high level for me, then I got a little bit tired.
"The conditions here are very humid, I am sweating a lot and in those conditions I suffer a bit. I was able to play aggressive in the fourth. He is an amazing player and has a great future."
There were several upsets in the women's draw, where Serbian seventh seed Ana Ivanovic was beaten 6-3 3-6 6-3 by Dominika Cibulkova of Slovakia, and she was followed out of the tournament by five more seeds.
|Brits on Tuesday (*approximate times, BST)|
|16:00 - Jo Konta v Louisa Chirico (US), court 11|
|18:00*- Laura Robson v Elena Vesnina (Rus), court 11|
|18:00*- James Ward v Thomaz Bellucci (Bra), court 7|
|18:00*- Aljaz Bedene v Ernests Gulbis (Lat), court 14|
|00:00 - Andy Murray v Nick Kyrgios (Aus), Arthur Ashe Stadium|
Draw opens up for Serena
Serena Williams was generous in her praise for 25-year-old Russian Diatchenko after a workout that last just 37 points, with the American winning 32.
"I told her I was proud of her for coming out and making this effort, knowing she was injured," Williams said. "That's a great effort."
Her chances of reaching the women's final were boosted even before the world number one began her title defence as seeds tumbled to leave the American with no other top-10 player in her half of the draw.
As well as Ivanovic, eighth seed Karolina Pliskova - who lost 6-2 6-1 to Anna Tatishvili - and 10th seed Carla Suarez Navarro failed to progress, while world number three Maria Sharapova withdrew on the eve of the tournament because of injury.
Former champion Svetlana Kuznetsova, seeded 30th, and former finalist Jelena Jankovic, seeded 21st, also exited on day one.
Williams' sister Venus, the two-time champion, did advance to the second round, beating Monica Puig - only her second victory since losing in the last 16 at Wimbledon.
Tennis tries mid-match interviews
The last time Pam Shriver was seen on a singles court at the US Open was in 1996, but the American caused quite a stir when she returned to the field of play - microphone in hand.
Shriver sat down next to Coco Vandeweghe and proceeded to interview the American after she had taken the first set off compatriot Sloane Stephens on Louis Armstrong Stadium in a match she went on to win 6-4 6-3. The tennis world was quick to react...
Fourth seed Caroline Wozniacki: "Did I just see Coco do an interview on court, mid-match, after the first set?? Surely you would wanna focus on the game out there? No?"
Russian player Elena Vesnina: "What was that??!"
British player Laura Robson: "Coco talking to ESPN during the match??? What???"
Coach and pundit Darren Cahill: "Big thanks to @CoCoVandey. 1st interview conducted mid-match with a player just aired on ESPN. Players choice after a set win. "
'I had the worst feelings of my whole life'
Mardy Fish delayed his farewell by at least two days with a stirring 6-7 (5-7) 6-3 6-1 6-3 win over Italy's Marco Cecchinato on Grandstand.
The 33-year-old American will retire after the tournament having suffered with an anxiety disorder for the last three years.
His last visit to Flushing Meadows in 2012 ended with Fish unable to take to the court against Roger Federer as he suffered a severe panic attack.
"It's still a constant battle, day-to-day sort of stuff," Fish said. "I work on the mental health side constantly. This tournament is where it all came crashing down and where I had the worst feelings of my whole life.
"That's a tough thing at my favourite tournament. So I sort of desperately wanted to come back and change that narrative. I feel really good."
Quotes of the day
"I can't remember a thing I said." The first ever mid-match interview did not leave a lasting impression on Coco Vandewehghe.
"I will not, definitely, this tournament. But who knows? Who knows what the future brings?" Novak Djokovic will not be chinwagging with Pam Shriver over the next two weeks.
"Who knows? Might have been my last match. Obviously, it would be great to be back here next year, but it's a long way to go." Another man pondering the future is Tommy Haas, whose 17th US Open is over at the age of 37.
"We're still in touch right now. I called him before my match. I'll call him after I do press and see what he has to say." Eugenie Bouchard gets back to winning ways after a couple of days under the guidance of Jimmy Connors.
"We don't talk about tennis." Venus Williams has not mentioned the words 'Grand Slam' to her sister.
"He destroyed me. I kept hitting to his backhand. I'm like, 'Why am I hitting to this guy's backhand?'" Serena Williams tested out the ping pong version of Stan Wawrinka's backhand.