Last year's finalist Jon Rahm joined defending champion Dustin Johnson in a group-stage WGC-Dell Technologies Match Play exit after a second defeat.
World number three and Spanish Rahm was edged out by Johnson in the 2017 decider, but both players have endured miserable returns to Austin this week.
A superb round from Adam Hadwin defeated Johnson 4 and 3 and eliminated the world number one before his final round-robin match with a 0-2 record, before Rahm failed to pull off a late comeback against Chez Reavie on Thursday.
Rahm was three down through 15 and gains on the next two holes could not deny Reavie, with the third seed's participation then ended by Kiradech Aphibarnrat's dramatic win over Keegan Bradley elsewhere in the group.
Marc Leishman, the 11th seed, also bowed out after losing 3 and 2 to two-time Masters champion Bubba Watson.
There was better news for four-time major winner Rory McIlroy – who claimed last week's Arnold Palmer Invitational – as he responded to Wednesday's surprise 2 and 1 defeat to Peter Uihlein with victory 24 hours later.
The Northern Irishman and former world number one prevailed by the same margin against Jhonattan Vegas and is now just half a point back in his group.
Phil Mickelson moved back into contention after a stunning turnaround in his match against Satoshi Kodaira, trailing by four through seven to recover and end on a roll and 1 up.
Tommy Fleetwood got back on track, too, with a huge 7 and 6 victory over Kevin Chappell, having been beaten on Wednesday by compatriot Ian Poulter, who then made it two wins from two a day later.
Reigning PGA Tour Player of the Year Justin Thomas (3 and 1 over Patton Kizzire) and Masters champion Sergio Garcia (2 up against Dylan Frittelli) also hold perfect records at the close of play on Thursday, with the pair edging towards the last 16.
Jordan Spieth and Patrick Reed will go head-to-head on Friday after the pair saw off HaoTong Li and Charl Schwartzel respectively to set up a group decider.
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