|BMW Championship third-round leaderboard|
|-21 J Thomas (US); -15 T Finau, P Cantlay (both US); -14 R Sabbatini (Svk); -13 J Rahm (Spa); -12 B Snedeker (US), C Connors (Can), L Glover (US); -11 R Fowler, K Kisner, X Schauffele (all US), H Matsuyama (Jpn)|
|Selected others:-10 R McIlroy (NI), T Fleetwood (Eng); -9 P Casey (Eng); -7 T Woods (US); -5 I Poulter (Eng), B Koepka (US); -2 G McDowell (NI), J Rose (Eng)|
Justin Thomas will take a six-shot lead into the BMW Championship's final round after breaking the course record by two shots on a rain-affected day three.
Thomas, 26, made two eagles and eight birdies in a third-round 61 to finish 21-under-par at Medinah.
The new record was only set on Friday when Hideki Matsuyama shot a nine-under-par 63 in Chicago.
Tony Finau shot a four-under 68 to sit second on 15 under with Patrick Cantlay.
“It's just one of those freaky days when you get in the zone,” Thomas told the Golf Channel.
“I hit the ball pretty unbelievable. It's not like I made any long putts. I hit it close to the hole and took advantage of some opportunities when I had them and got a couple good breaks.”
A thunderstorm forced play to be temporarily halted, with the leaders' tee times delayed for more than an hour.
Reigning Masters champion Tiger Woods shot his lowest round since February with a bogey-free five-under 67 on the course where he won the 1999 and 2006 US PGA Championships.
Woods, 43, says he now “has a chance” to qualify for the season-ending Tour Championship, which begins on August 22.
US Open champion Gary Woodland was one shot off equalling Matsuyama's record with an eight-under-par 64, but missed a seven-foot birdie putt at the 18th hole.
Northern Ireland's Rory McIlroy lies in a tie for 13th place on 10 under after a third-round 70.