Rory McIlroy is just four shots off the lead at the halfway stage of the BMW Championship.
His 67 leaves the world number 3 on eight-under par at Medinah.
The lead is held by Hideki Matsuyama on 12-under par after he broke the course record by two shots with an astonishing nine-under-par 63. It comes a day after both Justin Thomas and Jason Kokrak equalled the Medinah course record.
In doing so, the 27-year-old Japan player also took the BMW Championship lead after round two.
Matsuyama hit nine birdies and no bogeys to move to 12-under overall, one shot in front of Americans Patrick Cantlay and Tony Finau.
“It seemed like every birdie chance I had I made the putt,” Matsuyama told reporters.
Thomas shot a three-under 69 to move to 10-under overall, but fellow overnight leader Kokrak had a less successful day and fell back to six under after a one-over 73.
After going around in 66, England’s Tommy Fleetwood moved up to eight under alongside McIlroy.
Tiger Woods’s form remains inconsistent, getting five birdies but also four bogeys in a second consecutive round of 71.
Brooks Koepka also scored a 71, moving the world number one to five-under overall.
England’s Justin Rose shot a 73 and fell back to three under, one behind his compatriots Paul Casey and Ian Poulter.