Is that Thomas Pieters or Tommy Fleetwood?! The luscious-locked Belgian is going well, one under through eight. And he's in prime position for the best Tommy lookalike, too.

A beautifully-weighted light touch from Jon Rahm sees him down a 19-foot putt and that's two birdies in three holes (and another chance missed). The world number two has no Majors to his name, but will be a contender this weekend.

Meanwhile, Mickelson's wayward effort off the tee ends up costing him one with a five-footer lipping out. Rahm and Mickelson have now flipped scores, with the Spaniard on two under and the American one under.

Just six players from the early session finished under par, and only once in five men's US Opens at Winged Foot have we seen someone post a winning score in the red - so what do we reckon this afternoon? Sneaky feeling the USGA might just crank up the difficulty level tomorrow too...

The tee shot on this slight dogleg hole is partially blind. Finding the fairway will be the key to success with the green guarded by two deep bunkers on the front corners.

Image source, Getty Images

England's Eddie Pepperell was rolling along quite nicely a couple of hours ago, at one over after nine holes. But he's had a bit of nightmare on the back nine.

A double bogey and five bogeys coming home has seen him post an eight-over 78 and he's currently tied for last place.

Bryson DeChambeau is also in a bit of a pickle. Up on the fringes, eyeing a serious slant on the green, but he does well to skip it up just beyond the pin.

Tony Finau can't get up and down for par, nipping his putt narrowly wide.

DJ, meanwhile, is ticking off the pars.

For the third time in three holes, Phil Mickelson gives himself a huge challenge off the tee. Once again, the rough is the destination.

He's recovered twice for two birdies and needs to pull out something special again on the par-three third.

Justin Thomas, who has the clubhouse lead at five under par: "It is a beautiful course, from the tee, visually, the bunkering, the shape of the holes and the grass. It's a really good golf course."

Lee Westwood joins 7 others on -2 as he chases Thomas at the top of the leaderboard

-5 Thomas (F)

-4 Reed (F)

-3 McIlroy (F)

-2 Kokrak (F), Todd (F), English (F), Norris (7), Pak (a) (6*), Putnam (5*), Niemann (3), Westwood (3*)

Chance missed for Jon Rahm as he has a 16-foot attempt for a second birdie in a row, but it agonisingly stays out.

However, there's no mistake from Phil Mickelson as his second shot sets up a six-footer, which he sinks. Holes two, birdies two.

England's Paul Casey, the third man of the group, bogeys the second and is on one over.

Miss the green at your peril on the par-three third - as Billy Casper would tell you - and Tony Finau does just that, about five minutes after I suggested he was one to watch...

It'll be tricky lie for the American but he has avoided those ferocious bunkers.

Lee Westwood has done just about everything in the game, bar win a major. The 47-year-old, who has won 44 tournaments, may well be in the twilight of his career, but there's still a bit of fight in him.

He's started on the 10th and birdied the 11th and 12th holes and has followed that with a pin-seeker at the par-three 13th. The eight-foot putt stays up and the birdie run ends but an impressive start nonetheless.

The Englishman has twice finished third at the US Open - can he improve on that this week?

Phil Mickelson started with a birdie, as has another member of his playing group - world number two Jon Rahm.

The Spaniard also comes here as a man in form after he took the BMW Championship at the end of August when he edged out world number one Dustin Johnson in a play-off.

On the second, just as he did on the first, Mickelson sends his tee shot wayward into the rough, only to make a lovely recovery and the American has a chance for a second consecutive birdie.

Dustin Johnson, the world number one, is the man in form heading into this week - and the one decidedly richer after winning the Tour Championship. But can he conquer Winged Foot?

DJ steadies himself over a short but tricky par put at the second, and prods in. He's remains level.

Bryson DeChambeau sets himself up with a second consecutive birdie chance but sizzles it beyond the cup with his flat iron.

Tony Finau completes this trio and could be a good shout for a first major victory - a par, par start for him.

Tee shots must avoid the right rough on this slight dogleg right.

Several challenging hole locations include just over the deep bunker that guards the front of the green and back left under the branches of an enormous elm tree.

Image source, Getty Images

Image source, Getty Images

Wondering who's to blame for this wonderfully challenging course? The answer is A.W. Tillinghast, one of six golf course architects to be elected to the World Golf Hall of Fame.

He designed the West Course at Winged Foot, which was opened in 1923, after spending time at St Andrews and studying under Old Tom Morris.

Nicknamed Tillie the Terror, he once wrote it was the architect's job to "produce something which will provide a true test of the game and then consider every conceivable way to make the course as beautiful as possible".

There has since been extensive work conducted on the bunkers and greens in 2017, along with trees being removed

Image source, Getty Images

Phil Mickelson may well have had a few nightmares over the years after what happened at Winged Foot in 2006. Needing a par on the last to win the US Open, he hit the ball off a hospitality tent on his way to taking a double bogey as Geoff Ogilvy took the title.

His first shot in 2020 is not a pretty one either as he misses the fairway, but he recovers in incredible style to move to within eight foot of the hole and then sinks the putt for a birdie.

Mickelson has been a US Open runner-up on six occasions and he's one under after one.

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Ireland's Shane Lowry has had a little longer than most to enjoy his time as Open champion after this year's tournament was cancelled because of this pesky pandemic.

The popular winner at Royal Portrush in 2019 has had a superb start at Winged Foot. He coaxed in a beautifully-weighted putt on the first for a birdie and then rattled another one in the front door on the second.

Cracking start for Bryson DeChambeau.

The big-hitting American said he was going to try and overpower the notoriously difficult Winged Foot this week and comes straight out the blocks with a birdie.

Shaun Norris is the only player still on the course to be near the top of the leaderboard

-5 Thomas (F)

-4 Reed (F)

-3 McIlroy (F)

-2 Kokrak (F), Todd (F), English (F), Norris (5)