Sergio Garcia got the better of Ryder Cup team-mate Lee Westwood as he beat the Englishman by one hole in a topsy-turvy match at the WGC-Dell Match Play at Austin Country Club.
Westwood birdied the sixth and seventh to lead by two after conceding two consecutive holes early. But two bogeys, including a shot penalty on the ninth, allowed the World Number 14 to recover and go one up after a birdie on the 11th.
Both men, who have been integral in recent Ryder Cup victories for Europe, would exchange the next two holes before another bogey left Westwood trailing by two on the 14th.
With only one hole halved in the match, Garcia would need a 12-foot putt on the last for a half after a wayward tee-shot to claim the match.
"We're both trying to play well," said Garcia. "There were some really good things in the match; there were some things that weren't that great. But the match was nice.
It was nice to play. It was great spirits all the way. I just got really fortunate to come through with a win - Sergio Garcia
The other Group 13 contest saw Marc Leishman and Ryan Moore halve their match.
Jason Dufner shocked fellow American and World Number Five Rickie Fowler by claiming a 2 and 1 victory.
Byeong-hun An surrendered a three-hole advantage to halve his match with Scott Piercy in the other Group 5 encounter.
In Group 12, Rafa Cabrera-Bello completed an impressive start to his campaign after beating Hideki Matsuyama by one hole.
The Spaniard never trailed in the contest but overcame a fightback having led by three holes at the 11th before Matsuyama claimed the 12th, 13th and 14th.
A birdie on the 17th saw Cabrera-Bello regain his advantage but after driving the green, he three-putted the 18th to keep his nose in front.
"I felt pretty much in control throughout the front nine, three up through the turn," said Cabrera-Bello.
"Then I had a little bit of a messy start of the back nine. Hideki also played really well on those holes. I lost all my lead in just four or five holes.
"I told myself that these type of things happen in match play, that there's still a lot to play for. I really played well the last three holes."
Meanwhile, Dane Søren Kjeldsen was beaten 2 and 1 by American Kevin Kisner.
Group 4 saw World Number Four Bubba Watson halve his match against Patton Kizzire, while Argentinian Emiliano Grillo beat J.B. Holmes 3 and 2.