Jason Day’s plan to “just grind it out” paid off as he overcame a late rally from Denmark’s Thorbjorn Olesen to reach the second round of the WGC-Match Play Championship.

World No.11 Day hit brilliant approach shots to the final two holes of the Dove Mountain course to win 2 up and set up a clash with American Billy Horschel.

Marc Leishman, the only other Australian in the 64-man field, also had a long, tense struggle but made critical errors at key moments to be eliminated by Spain’s Sergio Garcia at the 22nd hole.

In a change from the usual day one carnage, just nine of the 32 first round matches ended in ‘upset’ wins with world No.6 Zach Johnson and No.8 Dustin Johnson the biggest casualties.

Steve Stricker, Lee Westwood, Ian Poulter, Luke Donald and Keegan Bradley were also ousted by lower-ranked opponents.

Day was 2 up over world No.60 Olesen through 14 holes but watched two birdie putts from the Dane drop on the next two holes to square the match.

But when Olesen missed the green on 17, Day stepped up from the fairway bunker and stuck it to eight feet to eventually clinch the hole.

An even better approach to three-feet on the last cemented his victory.

“I played as good as I could and I didn’t make a bogey out there,” Day said.

“I played solid golf but just the amount of stress and pressure you put on yourself, especially coming down the final few holes, it’s intense.”

Day refused to be rattled by the Dane’s late surge.

“I just thought don’t give up. Winning is everything.

“I’m just trying to grind it out and find a way to win and that’s pretty much it. That’s everything.”

Leishman made critical errors in the big moments to cruel his chances of an upset against Garcia.

The world No.63 hit driver into the ‘death’ bunker and an approach into the desert on the 18th, left a wedge short on the first extra hole but left his biggest error for the 20th hole.

With No.8 Garcia well short of the par 5 green in two and in the rough Leishman pulled his second shot from the fairway into a short-sided bunker and drew a terrible lie, scrambling for a par.

Garcia then clinched the match with birdie on the 22nd hole.

“There were plenty of chances for me but I hit bad shots at the wrong time,” Leishman said.