Austin - Thailand's Kiradech Aphibarnrat closed with back-to-back birdies to beat American Charles Howell 1 up on Saturday, joining major winners Bubba Watson and Justin Thomas in the World Golf Championships Match Play Championship quarter-finals.
Kiradech, the 28th seed, never led in the match until he won the final two holes with consecutive eight-foot birdie putts at Austin Country Club in Texas.
When Howell couldn't match his final birdie, the Asian star advanced.
"I've been behind all day. I just hoped the putts would go in," Kiradech said. "The last two birdies were incredible.
"I've been enjoying every minute. It's my goal every week to finish in the top 10 so I've done that. I can just go out now and have fun."
Kiradech booked an afternoon last-eight date with two-time Masters champion Watson, who eliminated 18th-seeded fellow American Brian Harman 2&1.
Watson, seeded 35th, parred the par-3 11th to seize a 2-up edge, the largest either player enjoyed to that point, and eagled the par-5 12th to seize command.
"I played pretty solid and I made some big putts," Watson said. "In that stretch I made the putts and he missed them.
"We're just focused on birdies. If we shoot 67 every day and get beat, we get beat."
Second seed Thomas, last year's PGA Championship winner, routed 50th-seeded South Korean Kim Si-woo 6&5 to reach a quarter-final clash against US compatriot Kyle Stanley, the 45th seed who dumped out reigning Masters champion Sergio Garcia 3&1.
Other quarter-finals will pit Sweden's Alex Noren against Australian Cameron Smith and England's match-play specialist Ian Poulter against American 32nd seed Kevin Kisner.
Noren thrashed US 19th seed Patrick Reed 5&3, with the American making just one birdie, while Smith birdied the last two holes to hold off English 12th seed Tyrell Hatton 2&1.
"I played pretty good all day," Noren said. "I had a lot of chances. I'm really happy with the way I played. It's tough to read those greens on a long putts. You've got to get close."
Poulter made seven birdies and never trailed in dispatching 2010 British Open winner Louis Oosthuizen 2&1. After falling 4-down after 13, the South African charged with three birdies but missed a 16-footer at 17 to hand Poulter the victory.
"I knew Louis wasn't going to back off. He came on pretty strong," Poulter said. "I had to make a lot of birdies."
Kisner sank an eight-foot birdie putt on the 18th to edge 16th-seeded fellow countryman Matt Kuchar 1 up.
Round of 16:
Bubba Watson (USA x35) bt Brian Harman (USA x18) 2&1
Justin Thomas (USA x2) bt Kim Si-woo (KOR x50) 6&5
Kiradech Aphibarnrat (THA x28) bt Charles Howell (USA x59) 1 up
Kyle Stanley (USA x45) bt Sergio Garcia (ESP x7) 3&1
Alex Noren (SWE x13) bt Patrick Reed (USA x19) 5&3
Cameron Smith (AUS x46) bt Tyrrell Hatton (ENG x12) 2&1
Ian Poulter (ENG x58) bt Louis Oosthuizen (RSA x25) 2&1
Kevin Kisner (USA x32) bt Matt Kuchar (USA x16) 1 up
Afternoon quarter-final pairings
Kiradech Aphibarnrat (THA x28) v Bubba Watson (USA x35)
Justin Thomas (USA x2) v Kyle Stanley (USA x45)
Alex Noren (SWE x13) v Cameron Smith (AUS x46)
Ian Poulter (ENG x58) v Kevin Kisner (USA x32)