Northern Irishman Rory McIlroy recovered from his faulty first day at WGC Matchplay in Texas with a 4-3 victory over American Lanto Griffin.
The four-time major winner, who found a pool in his loss to Ian Poulter, led the 46th seed from the first to the 15th and final hole.
England’s Poulter is in the best position to win Group 11 after a thrilling victory over Australian Cameron Smith.
Poulter, seeded 60 out of 64, faces Griffin in his final group game.
The 2010 champion had three points before the 16th, but lost the next two holes. After Smith pared last, Poulter held his nerve to match his rival and secure his second victory.
McIlroy is hoping to defeat Smith and his Ryder Cup teammate slipping for a chance to advance to the knockout stages this weekend.
The European pair are two of 64 players in Austin split into 16 groups of four, with only the group winners reaching the next stage.
In the event that two or more players in a group equal the highest totals, a hole-by-hole stroke play elimination game will determine which player advances.
Second seed Justin thomas was eliminated from the tournament thanks to a 2 & 1 loss by fellow American Kevin Kisner, his second consecutive loss in Group 2.
Kisner was four places after 10th and although the 2017 US PGA Champion briefly rallied, he fell short to the defending champion.
41st Scottish seed Robert mcintyre almost clinched a shock victory over world number one Dustin Johnson.
The 24-year-old was two after the 15th hole, but the Masters champion won the next two, including an eagle on the 16th. Group 1 rivals tied the final hole as the game ended in four.
Fleetwood and DeChambeau score their first victories
From Spain Sergio Garcia is well positioned to win group eight after a 3-2 victory over England’s eighth seed Tyrrell Hatton.
Worksop from Lee Westwood, beaten by Garcia on Wednesday, beat Englishman Matt Wallace 5 & 3.
From England Paul Casey won his first victory in Group Nine after defeating American Talor Gooch 3 and 2.
There was better news for America’s fifth seed and US Open champion Bryson DeChambeau, who rebounded from his first loss to claim a 2-1 victory over South Korean Si Woo Kim.
Group five will descend to the wire after Southport Tommy Fleetwood beat Frenchman Antoine Rozner 4 & 3.
Rozner knocked out DeChambeau on Wednesday, while Fleetwood will face the American in their final group game on Friday, having tied their opener against Kim.
There was also a first Group 15 win for England Matt Fitzpatrick, who defeated Canadian Corey Conners 5 and 4.