Rory McIlroy and world number one Dustin Johnson were on the end of two major upsets following the first day of the WGC Dell Technologies Match Play.
Fresh off winning last week's Arnold Palmer Invitational, four-time major champion McIlroy was defeated 2 and 1 to Peter Uihlein in Austin on Wednesday.
Former world number one and 2015 winner McIlroy was five holes down through 13 holes, but won three straight to give Uihlein something to think about down the stretch.
"I made him earn it at least," McIlroy said after his round. "I made the score line a little more respectable. I just came away a little flat. I didn't really necessarily play badly. He played pretty well. It was a few under through nine, and got down early and he didn't make a bogey all day. So it was — it was hard to sort of claw my way back.
"It was gusty out there, the conditions were a little tricky. As I said, I made a run at him at the end, but it was a little too late."
Defending champion Johnson also lost his opener, falling 3 and 1 to Bernd Wiesberger.
The match was all square through 14 holes, but Wiesberger won holes 15, 16 and 17 to earn the shock victory.
While Wiesberger still has a lot of work to do to win this week, beating Johnson could help him make the Ryder Cup.
In a smaller upset, red-hot Englishman Tommy Fleetwood was defeated by match-play legend Ian Poulter.
Proving the world does still make sense, Jordan Spieth (2 and 1 against Charl Schwartzel), 2016 champion Jason Day (4 and 2 over James Hahn), Patrick Reed (3 and 2 against HaoTong Li) and Justin Thomas (2 up over Luke List) all won their first matches.
Masters champion Sergio Garcia had an eventful day, which saw him triumph 1 up over Shubhankar Sharma.
His first match, though, was highlighted by an unthinkable moment from the car path on the 12th hole against Sharma.
Garcia found the concrete from his tee shot and the Spanish star decided to remove his shoes play the shot in just his socks.
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