England’s Justin Rose shot a seven-under-par 63 to move into second place after the second round of the BMW Championship in Philadelphia.
Rose, 38, finished the day 11 under, two off the lead, to climb the leaderboard as Rory McIlroy and Tiger Woods moved in the opposite direction.
McIlroy had a one-under 69 for a nine-under total, one shot ahead of 14-time major winner Woods, who bogeyed his final two holes in a level-par 70.
Xander Schauffele leads on 13 under.
The American shot a six-under 64 on a day when tee times were brought forward because of the threat of bad weather.
McIlroy’s 69 saw him fall six places to joint-seventh on nine under, while Woods is tied for 12th.
England’s Tommy Fleetwood sits one shot behind Woods after hitting eight birdies for an eight-under-par round of 62 to charge up the leaderboard.
Woods followed his 62 on Thursday – his lowest opening round since 1999 – with three birdies and three bogeys for a level-par 70.
The American, who was this week named as a wildcard pick for the Ryder Cup, said on pgatour.com: “I hit it just as good and putted it just as good. Nothing went in. That’s the way it goes.
“That round today was easily six, seven under par. It turned into even par which is not what I needed to do.”
Schauffele narrowly missed out on an automatic spot in Jim Furyk’s United States Ryder Cup team but could earn the fourth and final wildcard pick with a strong performance this weekend.
He said: “I feel like I’m sort of on a mission here. I have lots to prove to myself… and I just want to win and just handle my business.”