Rory McIlroy remained unbeaten, Tiger Woods suffered a critical loss and defending champion Bubba Watson and two-time winner Jason Day were eliminated at the WGC-Match Play Championship.
The 64-player showdown featuring the world ranking leaders at Austin (Texas) Country Club starts with three days of group play to determine 16 berths in weekend knockout matches to decide a champion.
Fourth seed McIlroy defeated South Africa’s 47th-seeded Justin Harding 3&2, giving him a 2-0 record and group lead.
McIlroy, who has never trailed in two days, needs only a draw with English 32nd seed Matthew Fitzpatrick on Friday to advance.
Brandt Snedeker never trailed in beating 14-time Major champion Woods 2&1 to share the lead in an all-American group with Patrick Cantlay, who beat Aaron Wise 4&2.
For any chance to reach the weekend in his first Match Play start since 2013, three-time winner Woods must beat Cantlay on Friday and have Wise defeat or draw with Snedeker.
“My own kids were probably rooting for him,” Snedeker admitted.
England’s second-seeded Justin Rose was 3-down with four holes remaining but charged back with long birdie putts to halve with compatriot Eddie Pepperell on a day when 17 of 32 matches went to the 18th hole.
Rose must beat American 22nd seed Gary Woodland, a 1-up winner over Argentina’s Emiliano Grillo, on Friday to advance.
Watson was eliminated with a 2&1 loss to fellow American Billy Horschel while 12th seed Day was ousted with his second defeat, falling 4&3 to Sweden’s Henrik Stenson.
Stenson plays Jim Furyk, who eliminated five-time Major winner Phil Mickelson 1-up, on Friday to decide a spot in the last 16.
South Africa’s 40th-seeded Branden Grace beat World No. 1 Dustin Johnson 1-up. A 38-foot birdie putt at 17 by Grace proved the difference after Johnson missed a 17-foot birdie putt at 18.
China’s Li Haotong edged US third seed Brooks Koepka 1-up to eliminate the reigning US Open and PGA champion from title contention.
Aussie Marc Leishman beat Scotsman Russell Knox 2-up for the group lead after Thailand’s Kiradech Aphibarnrat beat US sixth seed Bryson DeChambeau 2&1.
