Jimmy Walker, arguably the hottest player in the game, drew first blood at the WGC-Accenture Match Play Championship with a commanding 5&4 win over South Africa's Branden Grace in Marana, Arizona on Wednesday.
American Walker, who has already triumphed three times on the 2013-14 PGA Tour, never trailed in his first-round match at Dove Mountain before sealing victory with a 15-foot birdie putt at the par-four 14th.
He will next play fellow American Rickie Fowler, who pulled off an upset 2&1 win over matchplay expert and 2010 champion Ian Poulter of England.
In other early matches, Bubba Watson clawed his way back from two down after 12 holes to battle past Finland's Mikko Ilonen 2&1 while South African George Coetzee won 3&1 against a rusty Steve Stricker.
Walker, making his debut in the elite World Golf Championships (WGC) event, was delighted to maintain his red-hot early season form.
"I played pretty solid all day, hit a lot of really good shots, made some birdie putts," Walker told reporters. "You've got to go out and continue to hit good shots and make good putts.
"Branden had a couple of three-putts early in the round and that got me up to a pretty good little lead. Just kind of stayed nice and steady and then closed it off with two birdies there at the end."
Fowler took advantage of a sub-par performance by Poulter, who is renowned for his steely matchplay prowess, especially in the Ryder Cup.
"I knew it was going to be a tough match today, no matter if Poulter is not on his game," said Fowler. "He wasn't playing great today, but I knew he was going to find a way to hang around.
"Obviously it feels good to get a win against him, against anyone. I'm excited for tomorrow."
Fowler knows he will have his hands full against Walker, who won the season-opening Frys.com Open in October before adding further victories at the Sony Open in January and the Pebble Beach National Pro-Am earlier this month.
"He's best player in the world right now, coming off three wins," said Fowler. "He's going to be tough to beat. I'll have to be on top of my game and make some putts."
Left-hander Watson, who clinched his fifth PGA Tour title at the Northern Trust Open on Sunday, was relieved to pull out a comeback win with four birdies in his last five holes.
"I fought hard," said Watson. "My caddie just said, 'Keep going, keep going, give me one hole, give me one hole.' He kept pushing me and somehow it came out to me winning.
"It's a just short week. You have one less day than normal to prepare, so the energy level is just not where I want it to be. Hopefully some rest today ... be ready tomorrow."
In other matches, former world number one Rory McIlroy of Northern Ireland was all square with American Boo Weekley after five holes while top-seeded Swede Henrik Stenson was one up on Thailand's Kiradech Aphibarnrat after one.
U.S. Open champion Justin Rose of England, the second seed, was scheduled to play against American Scott Piercy in one of the day's late matches.
(Reporting by Mark Lamport-Stokes in Los Angeles; Editing by Gene Cherry)