Dustin Johnson cruised into the last 16 of the WGC-Dell Technologies Match Play, where Jordan Spieth and Sergio Garcia were among the high-profile early exits.
The world No 1 saw off Ryder Cup colleague Jimmy Walker 5&3 to set up a knock-out clash with Zach Johnson in Texas, where eight out of the top 10 seeds failed to progress beyond the group stage.
Garcia was eliminated after being thrashed 6&4 by compatriot Jon Rahm and Spieth failed to qualify after halving his must-win match with Ryan Moore, while Rory McIlroy's dead rubber with Emiliano Grillo finished all square.
Tyrrell Hatton was knocked out after being handed a penalty in a three-man play-off, with Justin Thomas and PGA Champion Jimmy Walker also heading home.
Johnson made a lightning start and was six ahead inside seven holes, only for Walker to reduce the deficit with a birdie at the 11th and hole-out eagle at the next.
Walker holed a putt from the 13th fringe and almost drained a 30-footer at the next, before Johnson sealed victory with a close-range birdie at the 15th.
Phil Mickelson continued his fast start to the week by defeating JB Holmes 6&5 to book a meeting with Marc Leishman, who needed a second extra play-off hole to see off Lee Westwood and Pat Perez.
Paul Casey and William McGirt both progressed with 100 per cent records after wins against Charl Schwartzel and Andy Sullivan respectively, with McGirt set to face Soren Kjeldsen in the last 16.
Matthew Fitzpatrick claimed a 2&1 victory over Justin Thomas in Group Six to set up a play-off with Kevin Na, who had lost by the same margin to Chris Wood, where the American prevailed with an opening-hole birdie.
Bill Haas holed a 40-yard pitch to stay alive in his play-off with KT Kim before winning on the sixth hole, while Ross Fisher also needed extra holes to edge past former Open champion Louis Oosthuizen.
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