The Northern Irishman currently sits 28th in the FedEx Cup.
罗里·麦克罗伊 signed for a 64 to take a share of the lead at the BMW Championship as he aims for a spot in the Tour Championship.
The Northern Irishman carded four birdies on the front nine in Baltimore and an eagle on the 16th helped him to eight under.
McIlroy currently sits 28th in the FedEx Cup with only the top 30 after the weekend going on to 亚特兰大 下周.
The 32-year-old shares top spot with US Open winner 琼·拉姆 and American Sam Burns.
A shot off the leading trio is Sergio Garcia who had a clean round of 65, 尽管 18 players went round in 67 or less on Thursday.
England’s 保罗·凯西 could have been among them but bogeyed the 18th, and Ireland’s Shane Lowry carded a one-under 71 for a share of 47th alongside Lee Westwood.