Justin Thomas remains on course to become world number one as booked his place in the semi-finals of the WGC-Dell Technologies Match Play in Austin.
The American needs to win the tournament to replace Dustin Johnson at the top of the world rankings.
Number two seed Thomas had moved into the quarter-finals with an impressive 6&5 victory over South Korean Si Woo Kim in Saturday’s last-16 showdown.
Thomas, though, was made to work hard to progress through to Sunday's finale when he came from behind to see off compatriot Kyle Stanley 2&1.
Stanley, the world number 49, had earlier defeated 2017 Masters champion Sergio Garcia, and moved ahead after Thomas dropped a shot on the second.
However, it was all square when Thomas took the par-five sixth, only for the match to go into the turn all square again.
Thomas then put himself in the driving seat at three up after 12, and while Stanley clawed a hole back with a three at the next, the world number two closed out victory on the 17th.
Bubba Watson will be his opponent in Sunday's first semi-final after the two-time Masters champion beat Thailand's Kiradech Aphibarnrat 5&3.
The match was all square over the front nine before Watson started to find his range as the American claimed four consecutive holes to take control.
Watson, who is set to delay a planned family break after his unexpected advance through to Sunday, said on pgatour.com: “I keep advancing, and that is the key.
“We have been working on it (putting). The engineers changed the loft, basically took over my putting and said ‘here is what we are doing for you’. It has been working for the last couple of weeks.”
Ian Poulter's hopes of qualifying for Augusta suffered a setback after his comprehensive 8&6 defeat to American Kevin Kisner.
Englishman Poulter, who had beaten South African Louis Oosthuizen in the last 16, needed to reach at least the semi-finals to have a chance of climbing into the world's top 50 by Monday's deadline, which would guarantee him a berth in the field at Augusta.
However, the American raced into a six-hole lead by the turn, with his comfortable victory then a formality.
Swede Alex Noren completes the semi-final line-up, having beaten Australian Cameron Smith 4&2.
WGC Match Play quarter-finals:
Bubba Watson bt Kiradech Aphibarnrat (Tha) 5 & 3
Justin Thomas bt Kyle Stanley 2 & 1
Alex Noren (Swe) bt Cameron Smith (Aus) 4 & 2
Kevin Kisner bt Ian Poulter (Eng) 8 & 6
