PGA Tour writer Brian Wacker has been keeping an eye on the Spieth's this week. The world number two wasn't far away on this latest par three and will have one more chance at the par three seventh in a wee while.
- Golf's final major of 2015 at Whistling Straits, Wisconsin
- Clubhouse: American Dustin Johnson leads on -6
- Clubhouse: Rory McIlroy -1, Jordan Spieth -1 & Zach Johnson +3
- Clubhouse: Sweden's David Lingmerth the best of the afternoon starters on -5
- Clubhouse: Justin Rose & James Morrison -3, Tiger Woods +3
And so all the talk was about a certain two...
But Jordan Spieth and Rory McIlroy had to dig deep while a familiar face surged early on in a major championship...
So is this finally Dustin Johnson's time to land a major? Or will the pack hunt him down? We will be live texting again tomorrow so please come back for more.
Thanks for all your tweets and interaction tonight. Sleep well. Dream of birdies.
The great thing about golf is they do it all again tomorrow.
Some key tee times: Dustin Johnson - 19:20 BST, Rory Mcilroy and Jordan Spieth - 14:05 BST, Tiger Woods 20:30 BST, Luke Donald and Graeme McDowell - 13:45 BST.For a full list, click here.
Phil Mickelson in contrast has hit just four of 14 fairways today yet ends level par and goes close to birdie on 18 with a long putt from left to right.
Rory McIlroy - after a one under 71 - talks to Sky Sports: "It was a game of two nines really trying to hold on the front nine and then a few more chances on the back. It's great to be back, I was quite nervous on the first tee. The two shots on the second hole settled me down. The ankle feels great, it's felt great all week, it's not an issue and I've got full confidence in it.
"I took a trip to Haiti before the US Open in 2011 and that gave me a huge sense of perspective. To be out of the game recently was sort of nice. It made me realise that sometimes I get too wrapped up in what I'm doing and maybe it gave me some perspective going forward."
David Lingmerth - after his five under finish - speaks to Sky Sports: "I got off to a great start in tough windy conditions, a few birdies kind of got me going. You can't relax out there, you have to try to be in control of what you're doing the whole way."
The 18th hole claims a big scalp in Rory McIlroy. "Ha ha ha," chuckles the horrible final drag as the world number one can't get up and down and watches his 20 foot par putt roll away.
Still, one under after day one of the US PGA Championship, what would McIlroy have given for that when he pulled this face and broke the news of his horrible ankle injury in July?
The Open champion Zach Johnson has had a day of volatility - he ends plus three, can Jordan Spieth be the only player in the group to par 18? He can.
What's the story? Rory and Spieth end one under for day one.
There weren't too many thrown clubs by David Lingmerth today. What a round and what an opening nine to lay the foundation.
At five under through the turn he ends the day on the same mark after a birdie-bogey run on his 14th and 15th hole.
There's around £1.2m on offer for the winner this week. That would be his biggest payday by far as a professional golfer.
So to the marquee group as they come up 18, Rory McIlroy to fire into the green before Jordan Spieth. It's off line but leaves a chip with lots of green to work with and Spieth will leave what looks like a certain two-putt . Remember this hole is the hardest on the course today so players will bite your hand off for par.
Golf Channel writer Randall Mell is watching Phil Mickelson and guess what, Lefty has hit a wayward tee shot. He's done it on every hole so far almost so why stop on 17 I guess?
The bunker shot he has to play is just a hack, a hit and hope and it leaves a massive putt for par. He'll be going back to level par at best. A cat has nine lives, Lefty has had a dozen today and it looks like they've run out.
This golf course can damage you. Were any of you reading when Adam Scott started birdie-birdie? He ends four over for the day.
Phil Mickelson - I told you was in the water on 16 - escaped the wet stuff and guess what, he managed to make birdie on the par five.
Apologies if you're a Phil fan but it did genuinely look like his ball had missed the fairway. He's been like Houdini today. He could have been way, way, way over par but for some stunning invention, big putts and some might say, good fortune.
The 18th hole waits many of these players. It's grizzly to say the least. Measuring 520 yards as a par four it's long and has only given up five birdies all day. Brooks Koepka is a big hitter yet has just smashed his third into the green and can't make par from range, like many others, he will have to work just to make bogey.
ESPN golf writer David Sobel is on point as Rory McIlroy moves to within four of the lead with birdie at 16.
Jordan Spieth - perhaps sensing the need to move forward at a key time - rolls in for birdie on 16.
That's perhaps surprising one a hole which began with his "holy snap hooks" shout after his tee shot. The US Open and Open champion cracked a great third shot into the green, controlling it with spin to leave 12 feet or so.
Would one under be a great day for him? Or is he greedy? Two under maybe?
Phil Mickelson may well be in the drink.
"I lost it, did that stay fairway," he asks. We hear a shocked "what" from the American as someone probably tells him his ball is in trouble.
Another wayward tee shot looks like it may prove costly.
As we told you, officials are timing the play of Jordan Spieth and Rory McIlroy. Spieth is visibly rushing on this par five, jogging around in a bunker and generally not looking his ice-cool self. Both players have a wedge left into the green on this par five to set up birdie.
Jogs out of the bunker, smacks that troublesome sand off each shoe, Phil Mickelson has just done what he usually does and put a shot from the trap to within a foot.
Lefty has probably been in some sort of trouble on a dozen of the 15 holes he's played - either off the tee or with his second shot.
In what feels like a copy and paste moment, Rory McIlroy and Jordan Spieth will do with pars on 15. Spieth's up and down was champion-like, McIlroy's very close birdie putt shows he's not far off being right on song.
And while we're talking pars, Luke Donald chips out from among a crowd of spectators and salvages one from real trouble with a gutsy putt.
And we have one leader again. David Lingmerth can't roll home a six footer and drops back to five under. Dustin Johnson did the damage this morning and probably has his feet up now as others around him fail to reach his heights.
There's an official following Rory McIlroy and Jordan Spieth's group like a shark looking for a feed. It would appear they are on the clock for slow play.
McIlroy will have a putt for birdie of about 20 feet, Spieth has to get up and down from a shade short of the green for par, his wedge is top stuff and gives him a good chance.
Rory McIlroy, left off the tee on 15, Jordan Spieth lands in the same area and lets off an audible yelp of anger. The pair stroll down the fairway and converse like best buds.
Brooks Koepka is in trouble of an all together different level. Firing from the rough into what looks like deeper rough. If you've just tuned in, he was four over after nine holes, one under after 14 and is now level par and in a right mess on 16.
So Dustin Johnson is prominent on day one of a major - no news there, but did you see this bloke mounting a challenge?
David Lingmerth has played 24 tournaments this year, making the cut 15 times. The Swede has a chip and putt for par on 15.
Luke Donald has ticked along nicely today, a couple of birdies and bogeys for good measure. Getting home in a red number would be a fine result and he can reach one under if he nails a birdie putt on 16. His third into the green has a tonne of height and leaves around 25 feet.
Difficult to know how Phil Mickelson remains level par after 12. Lefty has hit three out of nine fairways and made only 42% of greens in regulation. No wins this year for the 2005 US PGA champion, although he did finish runner-up to Jordan Spieth at the Masters.
Make that level par through 13.
Jordan Spieth takes a divot the size of many front lawns on 14 and the spin he generates is colossal, leaving a long putt for birdie. Not to be outdone, Rory McIlroy spins his approach back past the flag stick to leave an outside birdie chance.
Brooks Koepka, the steamer in the field, has work to do to make par so his run of birdies are over but can we have a new leader? WE CAN. David Lingmerth, your name up in lights sir. A rock-solid birdie putt from 10 feet was never in doubt.
Graeme McDowell has tasted major success at the 2010 US Open of course. Not too sure a cap and white shirt go well together though.
"Go hard," shouts Graeme McDowell as he tonks one into the 569-yard par five 15th.
This has some hang time, in it comes to the runway and that landing spot on the front of the green offers some roll, a stunner.
Can he convert, it's right-to-left from 12 feet and raise that hand G-Mac - birdie time.
A safe par for Rory McIlroy and Jordan Spieth on 13, more than can be said of Zach Johnson who drops a shot for the second consecutive hole.
For those on Brooks Koepka watch, he is over halfway to a PGA Tour record. Mark Calcavecchia rattled off nine birdies in a row at the 2009 Canadian Open.
Would Rory McIlroy take one under for his round? It has been tricky after all. His putt for birdie is a bit short on 13 but should be converted for par.
He'd love a bit of what Brooks Koepka is showcasing at the moment. The young American - in dashing blue trousers - is shining bright on this course right now - he drains another monster putt for a fifth-straight birdie. Bring in the fire department, this kid is blazing a trail.
Sangmoon Bae making the most of his freedom, he's three under after 12. Bae, who has won more than $2m this season, was recently told he'll have to start a two-year stint in the Korean army at the end of this season, where he will earn $130 a month. Ouch, in more ways than one.
Ouch again, double bogey at 13, back to one under.
The words "Adam Scott is my fancy" were about to roll off my tongue so it's perhaps unsurprising the Australian drops four shots in two holes. He becomes what seems the latest in a long line of players today to totally flunk a par three - carding six - and follows with a bogey. Ugly.
Kopeka's latest birdie comes with a sweeping chip which takes a break and makes its way into the cup. Delightful.
Phil Mickelson takes his third from the middle of the 11th fairway - a par five remember. The wedge sounds crisp, he likes it, pitches, lashings of backspin... it's in!! No. One more turn of the ball and it would have dropped. A tap-in birdie to return to level par.
"Oh my gosh Zach," says Johnson to himself as his tee shot floats high and wide into the rough on the 12th.
Jordan Spieth goes next, woosh goes his iron, he looks nervously as his ball pitches but runs a little far from the flag on the green. Rory McIlroy is nice and safe on the putting surface.
Spieth from the fringe... stunning. A perfectly judged chip and will this spark a roll. Par for McIlroy, bogey for Johnson.
Spare a thought for Cameron Tringale. The American was loving life, cruising along at level par and then bang, like a hurricane racing in from Lake Michigan he feels the force of Whistling Straits and folds like a paper napkin.
A quite stunning eight shots dropped in six holes leaves him eight over after nine. His triple bogey on the par-four eighth was gruesome. Ouch.