Rory McIlroy makes his fourth successive birdie, although it could have well been an eagle of the par five 10th. He's now at three under.

One of the best momentum players on the tour.

Justin Thomas makes his birdie to go to one under, while Tiger Woods finally records one himself in this round to return to one under. He started the day at two under.

So the defending champion finds a spot in the rough and receives treatment to what seems either his left knee or the left side of his hip.

He seems OK to carry on.

American world number six Brooks Koepka is playing some more solid golf as he looks to tee himself up (every pun intended) for an assault on his third successive US PGA come Sunday.

A par on the par three 11th, frankly salvaged after a poor strike from the tee, keeps him at six under - two behind clubhouse leader Li Haotong. The Chinese golfer probably can't believe he still holds the lead.

England's Justin Rose is quietly going about his business. He's birdied the 10th and is now at five under.

He's one of those players that will sneak into tied third on Sunday.

Cheers for that Ben, Saj here again.

Now then. Collin Morikawa at four under eh?

So the 23-year-old is a hot prospect. He recently won the Workday Charity Open a month after finishing runner-up following a play‑off defeat at the Charles Schwab Challenge.

He's up to 12th in the world and has just birdied the par-three 11th with a 20 footer.

I very much like the cut of his jib.

Image source, EPA

Still no birdie for Tiger Woods today. In fact, he's just had to take a bogey at the ninth, leaving him two over for the day.

Justin Thomas drops a shot too so Rory McIlroy, playing in the same group, takes his time over his putt. Wise move, as he sinks it for his third straight birdie. Great finish to the front nine for McIlroy.

Guy Dixon: To be fair Jason Day was 4th to Tiger at the Masters last year so can't be ruled out.

Oh, Brooks Koepka is an inch from claiming an eagle on the 10th. A birdie is enough for him to join Jason Day on six under though. This should shake things up. How can Day react?

Daniel Berger's previous best finish at a major is a tie for sixth at the US Open in 2018 and he's been on a hot streak since the lockdown.

Although the 27-year-old missed the cut at the Memorial Tournament, he won the Charles Schwab Challenge, had a tie for third at the RBC Heritage and last weekend was tied for second at the WGC-FedEx St. Jude Invitational.

Blimey, now there's movement at the top of the leaderboard.

It's a double bogey for Jason Day on the 12th to drop to six under. And moments later Daniel Berger picks up a shot on the 11th to make it back-to-back birdies.

The American moves above Day to seven under, one behind Li Haotong, who is the outright leader once more.

The field is hitting just 51.7% percent of fairways. We're on course for the toughest fairways to hit at a PGA Championship since 2008 at Oakland Hills (48.5%).

Tiger Woods is just short of a birdie on the eighth.

Now Rory McIlroy's turn...and he only goes and sinks it! That's back-to-back birdies for the Northern Irishman to go back into the red. Has he now found his groove after a testing start to day two?

Brooks Koepka has a tough putt to make par on the ninth. And he makes it. Good save. The defending champion stays on five under.

Rory McIlroy finds the green on the par-three eighth but it's a big ask to claim a birdie.

Tiger Woods puts himself within similar range.

Now then, what's going on over in San Francisco?

Daniel Berger has claimed a birdie on the 10th to move to six under. Was an inch short of an eagle.

BBC Radio 5 Live Sports Extra

Cheers Saj, and I'll begin by putting you out of your misery with tonight's teaser: Who are the 10 men who spent the entirety of the 2010s in the top 100 - from 1 January 2010 to 31 December 2019?

Well take a bow Philip Hill because you got it spot on. They are: Rory McIlroy, Justin Rose, Dustin Johnson, Sergio Garcia, Adam Scott, Lee Westwood, Louis Oosthuizen, Phil Mickelson, Rickie Fowler and Matt Kuchar.

However, there may have to be a steward's inquiry...Iain Carter is convinced American Ryan Moore did it too.

I'll hand over to Ben Collins for a bit as I grab some tucker.

A much needed second birdie, on the seventh, for world number one Justin Thomas. He began the day at one over and now is one under.

The projected cut remains at one over and the recent St Jude winner should be OK for the weekend.

Guy Dixon: Has Adam Scott been mentioned for being in the top 100 from 2010 until 2019?

Philip Hill: Rory, Rose, DJ, Garcia, Adam Scott, Westwood, Oosthuizen, Mickelson, Fowler, Kuchar.