All pars at the 13th for this group.

Robert MacIntyre will be pleased with how he's managed to keep mistakes off his card since that solitary bogey at the third. There aren't many bogey-free rounds out there so it's steady stuff from the Scot.

A bit like Brooks Koepka earlier on, Tommy Fleetwood is hitting plenty of lovely shots but the putts ain't dropping.

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Scottie Scheffler joins the six other joint-leaders at three under.

The world number one has now made four birdies in the past six holes and his putter has caught fire.

The defending US PGA Champion clearly doesn't fancy relinquishing his crown.

Shane Lowry punches a low iron shot down the right of the fairway after drifting into the rough from the tee. And with his par under threat finds a lovely little chip to three feet before tidying up.

Viktor Hovland would love a birdie putt from there. The Norwegian has recovered a little with two birdies after those four earlier bogeys but can't drop in a chance to pull back another stroke back from 10 feet.

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Justin Rose looks perplexed. Faced with a little pitch-and- putt shot he comes up a yard or two short and his ball begins to trundle back down the slope on the 11th green.

Scottie Scheffler and Matt Fitzpatrick, who sounds a tad annoyed on release, make no mistake in finding the correct tier of the green and will have birdie putts incoming.

As you were at the end of the 11th under cloudy Pennsylvania skies.

Justin Thomas chips on to the green but cannot quite get enough back spin to make it a realistic birdie chance and he two putts for par.

Neither Cameron Young nor Keegan Bradley can make any inroads.

Oof a stumble for Martin Kaymer at the seventh (his 16th) and he's dropped out of the lead.

This time, he was out of place after his tee shot and never recovered.

Aaron Rai dropped a shot at the 18th - his ninth - but he continues to be dialled in with his irons as a pinpoint approach at the second sets up his fourth birdie of the day and he moves back to two under.

Collin Morikawa likes that....the American is faced by a mid-range putt that shifts from left to right. And just as it looks like it's sliding past his ball grips the right side of the cup and disappears for a birdie.

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Justin Rose is currently tied for 127th in terms of strokes gained off the tee. He has barely hit a fairway all day and misses another on the 10th.

He has defended his decision to switch to McLaren Golf irons having recorded finishes of T65 and T45 since moving to new equipment but clearly something is amiss, even if he does recover to save his par on the 10th.

While he is toiling and Matt Fitzpatrick is grinding around Aronimink, Scottie Scheffler is warming to the task in hand and nails a 28-foot putt for birdie.

All you Akshay Bhatia fans out there will be disappointed.

The wiry American has just carded his third straight bogey over at 15 to further illustrate how this course can chew up a round very quickly.

He's back to level par.

Justin Thomas has a down-to-business expression on his face as he eyes up a 29-foot putt on the 10th.

The 33-year-old comes up a couple of feet short of the hole to leave himself a bit of a knee-knocker but he duly tucks it away for par.

Par for Cameron Young while a bogey for Keegan Bradley takes him to two over.

We've seen how accessible the pin location at the 11th is with that backstop behind the hole and Chris Gotterup takes full advantage, running his ball up to the top of the hill and watching with glee as it runs back down to three feet.

A birdie for the American, but Tommy Fleetwood can't follow him in as the Englishman misses from 12 feet.

Just a par, too, for Robert MacIntyre but the Scot's putting together a fine round, which is exactly what he needed after a Masters to forget.

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I'd have put my mortgage on Scottie Scheffler get closer from there but he clips his third 15 feet past the pin from just off the front edge of the ninth green.

The American looks a little frustrated when his birdie putt slides past and he only collects a par.

Nothing doing for Matt Fitzpatrick or Justin Rose, who both fail to convert from 20 feet or so. Neither has really been able to gain any momentum today so far

Here comes Shane Lowry...

The 11th green can be a tough one but after a monster 325-yard drive, Lowry then flips a wedge from just inside 100 yards to just seven feet, and although his birdie putt was running out of legs it just had enough to drop into the cup for a three.

At two under, he's just a shot off the massed ranks of leaders at Aronimink.

Another tricky hole navigated for Martin Kaymer as he gets through the par-three fifth (his 14th) unscathed.

Teed to the fringe, putting from 70 feet and then tidying up for par.

Into the closing stretch for the two-time major champ.

Scottie Scheffler comes up short of the green on the 609-yard par-five ninth hole.

But neither Matt Fitzpatrick or Justin Rose are remotely close to the American, who again shows the value of finding the fairway off the tee, while his playing partners do not.

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Justin Thomas, trousers buffeting in the wind and white glove hanging out the back of his pocket, takes his time weighing up a slightly awkward putt on the ninth.

The two-time PGA Championship winner calmly steps up and rolls it in from six feet to end an impressive back nine three under and with a share of the lead.

Par for Cameron Young and a bogey for Keegan Bradley.

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Collin Morikawa starts his back nine with a bogey after finding the right rough off the tee - contrary to popular belief there's a real premium at Aronimink for finding fairways today.

It costs Morikawa a shot as he just can't get a run going.

After finding the fairway, Robert MacIntyre's towering approach from 177 yards lands nine feet short to set up a possible third birdie in his past four holes at the 10th.

But he can't convert as his ball lips out! Big chance gone.

Aronimink has bitten back at Akshay Bhatia as it has done for almost the entire field today. The American was sitting pretty on three under at the turn but has now made back-to-back bogeys on 13 and 14 to drop back to one under.

And with the wind getting up he has to buckle in and try and ride out the rest of his round.