Shane Lowry faces a battle to make the weekend after carding a one-over-par 71 to finish 10 shots adrfit of first-round leader John Huh at the Wyndham Championship in Greensboro.
The Offaly man's round began with a double bogey and he dropped four shots in as many holes before bouncing back with an eagle on five.
Only a closing bogey denied him a par finish.
Huh is the man to catch after five straight birdies and added a long eagle putt to shoot a career-low, nine-under-par 61 to top the leaderboard.
Huh leads South Korea's Sungjae Im by two shots at the PGA Tour's regular-season finale. Peter Malnati and Brandon Wu are tied for third at six-under 64.
Huh, 32, needed a good showing this week at Sedgefield Country Club to ensure his berth into the FedEx Cup Playoffs. He entered the week 111th in the points standings, with 125 qualifying for the first leg. Huh would shoot up to 39th if the tournament ended Thursday.
"I'm actually surprised I'm at the top of the leaderboard, yeah, to be quite honest with you," Huh said. "I didn't really feel my game was there, but it's one of those days where I took advantage of some good shots and good breaks, I think."
Huh made six birdies for a front-nine 29, including five in a row from the fourth. His 10 1/2-foot putt at the par-4 sixth was the only birdie tap outside 10feet.
At the par-5 15th, he drove the green in two and drained a left-to-right eagle putt from 38 feet out before adding his final birdie at No. 17.
"I knew it was going to be a quick one," Huh said of the eagle putt. "I hit a good stroke, hit my line. I was hoping to go and I got lucky that it hit the flagstick and went in the hole."
Im had two eagles on his card, making a 15-foot putt at the par-5 fifth and a21-footer at No. 15. His 63 featured just one bogey and gave him good standing to try to finish the regular season in the top 10 in FedEx Cup points. He entered the week 15th.
Wu made six birdies for a bogey-free 64, while Malnati bogeyed just once and eagled the fifth with a 28-foot putt. Both are comfortably in the field of 125for the FedEx Cup Playoffs.
"Maybe like 110th is maybe the lowest I've gotten on the FedEx Cup(leaderboard)," Malnati said of his season. "But I've hung out in that range where it's not completely comfortable, but I've never felt like my back was completely against the wall either."
A large tie at 5-under 65 included Brian Stuard, Aaron Wise, Austin Smotherman, Ben Kohles, Alex Smalley, Ryan Moore, Australia's Cameron Percy, Spain's Rafa Cabrera Bello and Canada's Michael Gligic.
Smotherman entered the week as the last man in the field of 125. After a bogey-free round with five birdies, he'd be safely in the playoffs if the Wyndham Championship ended Thursday.
Similarly, Stuard entered the week No. 137 in the standings and is projected at No. 124 based on Thursday's leaderboard. Though he knows what's at stake, he said he doesn't feel much pressure.
"I don't have much to lose," Stuard said. "I'm kind of not in a real good spot, so just trying to figure out how to play some good golf again and see what happens."
Another player not in a good spot: Rickie Fowler. He entered the week No. 123 in the points standings and is in danger of missing the cut and losing his chance at the FedEx Cup Playoffs following a one-over 71 Thursday. Fowler opened with a double-bogey 6 at the first hole, fought back to get to 1 under and dropped back again with a bogey-bogey finish.