McIlroy lets rip and his immediate lean to the left tells you that he's leaked it right. That was very nearly in the drink from McIlroy and about six feet from being beyond the hazard line... enjoying this?

Martin: Following the live feed on a frustratingly intermittent 3G signal in the middle of nowhere in France - this is riveting stuff - go Wee man !!!

Den from Tyrone: Stuck in French campsite with no tv and ropey wi-fi - hanging on every update to the live feed and going through fingernails rapidly !!!

Someone have a word with the French, after all they're hosting the 2018 Ryder Cup.

Mark in St. Andrews: Despite its reputation as the 4th major, the USPGA sure has thrown up some amazing finishes over the years.

Fowler has smoked his drive down the 18th and Mickelson follows him down there with his three wood, although he has to enquire as to where his ball went because of the fading light. Unusually, McIlroy is going to have a go as well, once Mickelson and Fowler have disappeared over the bridge...

Iain Carter
BBC golf correspondent at Valhalla

"What a player. This is really special. This is golf from a golfing great in the making."

Sweden's Henrik Stenson makes par at the last when he needed more but that's a round of 66 for 14 under. But the big story is happening behind him, where Rory McIlroy has bent in his birdie putt on 17 to open up a two-shot lead. Mickelson and Fowler need eagles up ahead, Rory needs something pretty ordinary for a play-off to ensue.

Northern Irishman Darren Clarke, external ‏on Twitter: At this stage of a major it's all about mental strength with all of them playing so well! Confidence helps and Rors has a lot right now!

Stenson's birdie attempt misses by not much but a par won't be enough, even if he makes it. McIlroy parachutes in at 17, he's got a chance to virtually kill things off...

Welshman Jamie Donaldson is in the clubhouse with a 71 for -8, Jason Day has doubled 16 to fall back to -8. Fowler made that par putt, that boy has some big old cojones. Mickelson and Fowler stay one off the lead on -14, Stenson comes up short with his third at 18, out of some muck, his race could be run.

Mickelson needs some of that old black magic and he's found some from somewhere, what a chip shot that is - he'll tap in for par and gird his loins for one last assault down the 18th, where eagles lurk. Pretty ordinary putt from Fowler, he's got a knee-knocker for par...

They're racing the sun now, but it looks light enough out there that they'll finish this evening - unless, of course, there's a play-off. Mickelson overcooks the green with his second into 17, Fowler leaves himself with a monster for birdie. McIlroy finds sand off the tee at 17, Stenson has doinked his approach head high into the gallery over the back of the 18th.

Mickelson finds sand of the tee at 17, the old gunslinger looks to have bent his barrel at the worst possible moment. Stenson pumps his drive down the middle at 18, a good second and it's eagle o'clock... McIlroy's birdie effort stays left, but he stays outright leader on 15 under...

Phil Mickelson has been golfing with the Gods at times today...

Image source, Getty Images

But his dropped shot on 16 brings an end to a run of 21 holes without a bogey.

McIlroy now leads for the first time since the second hole and it looks likely to stay that way after a fine approach at 16. Since that miraculous three wood at 10, McIlroy has looked totally locked in and in control. Fowler pulls out the big stick at 17 and gives it some humpty, glorious drive...

Mickelson hasn't hit his par putt, Rory is outright leader on -14 - and he just saw that happen back on the fairway. Fowler prods his par putt in, a noticeable lack of bonhomie between himself and Mickelson as they head for the 17th tee. Stenson saves par at 17, is now in a three-way tie for second.

Image source, Getty Images

Fowler has got a regulation 97-foot putt at 16, I'd probably need a seven iron from there... what a putt that is, but he's still got a five-footer for par...

One of the shots of the day from Fowler, somehow making it to the edge of the green with a nine iron. The things these kids can do nowadays. Stenson with a smart chip on at 17, should save par. Mickelson very nearly holes that chip but his ball lips out on the second or third bounce and races six feet past. We could have a new outright leader in a minute...

Mickelson comes up short with his second out of the fluff at 16, he'll have a little chip over the bunker front-left. Fowler has got a shot that could make or break him here, he's going to have to try to bend his second round the trees, from the edge of the 15th fairway. Off jogs his caddie to get some yardage, as McIlroy absolutely ruins his drive behind him...

McIlroy with a snaky one downhill at 15... didn't hit it, that was a little bit tentative. Wiesberger still hasn't made a birdie today, his birdie effort misses to the right and the Austrian remains -10. McIlroy pops in his par putt, stays tied with Mickelson on 15 under.

Jay Townsend
former European Tour golfer & BBC Radio 5 live pundit

"Rory doesn't look comfortable to me. Phil looks like there's no place he'd rather be."

McIlroy hit his drive 350 yards, leaving himself 110... that's decent, chance for birdie. Stenson chucks everything at his drive down 17, that's gigantic and straight. Mickelson with three wood off the 16th tee, and his ball just bobbles into the rough. Fowler going with the big stick... leaked it right, so right it's missed the water and ended up on the 15th fairway...