France's Victor Perez joined Americans Matt Kuchar, Billy Horschel and Scottie Scheffler in the WGC Match Play semi-finals with dramatic victories Saturday, the final four all seeded outside the top 30 for the first time.
US 52nd seed Kuchar, the 2013 winner and 2019 runner-up, defeated US 54th-seeded left-hander Brian Harman 2&1 to stay perfect this week at 5-0 and advance to a Sunday semi-final against US 30th seed Scheffler.
"I feel great," Kuchar said after sinking a 10-foot birdie putt at the par-3 17th to seal the victory. "I can't tell you how much fun I've been having.
"On top of that, it has been so intense. It's a lot easier to smile when putts are going in. Certainly there are a lot of nerves."
Perez, the 31st seed who ousted Spanish 39th seed Sergio Garcia 4&3, continued a fairytale run in his WGC Match Play debut, booking a morning date with US 32nd seed Horschel in the other semi-final at Austin (Texas) Country Club.
"I think it's the benefit of not knowing. Sometimes ignorance is a good thing in golf," Perez said of his first-timer success. "I feel like I'm going to keep on riding it."
Horschel edged English 21st seed Tommy Fleetwood in 19 holes while Scheffler outdueled Spanish third seed Jon Rahm 3&1 in the other quarter-finals.
"I feel pretty comfortable out here. I'm not overthinking it too much," Scheffler said. "Everything is going so fast out here. It's pretty simple, just kind of staying in the moment and hit good golf shots."
Horschel never led until the playoff hole, the par-5 12th, where Fleetwood sent his tee shot out of bounds and Horschel holed a tense five-foot par putt to clinch the victory.
"It's tough. Tom and I had a great battle all day," Horschel said. "I knew a par would probably win it but this isn't the easiest hole. I'm glad to win it and move on."
The 18-hole final will be played Sunday afternoon.
Rahm, the only top seed to advance from the group stages, fell 3-down after five holes to Scheffler, a match-play debutant and hometown hero who ousted Ryder Cup star Ian Poulter in the morning round of 16.
"Being able to take down those two guys... I think my game's trending in the right direction this week," Scheffler said.
The Spaniard won the par-3 seventh with a 3-foot birdie and birdied the par-4 ninth from seven feet to pull within 1-down, but Scheffler sank a six-foot birdie at the 10th and put his approach inches from the cup to win the par-5 12th and go 3-up. Rahm only won one hole from there.
Perez, who moved to Scotland to be with his dentist girlfriend and has embraced Scottish golf culture living near St. Andrews, could eclipse his biggest career title at the 2019 European Tour's Dunhill Links Championship.
Perez dropped the first hole with a bogey but charged from there, taking the second and third on birdie putts from inside five feet, and after Garcia leveled by winning the fourth, Perez birdied to win the par-5 sixth and parred to win the eighth at go 2-up.
Garcia found water off the 13th tee and lost the hole and Perez closed him out by winning the 14th on a birdie putt from just inside 10 feet, but felt his best golf came in a 5&4 morning win over Scotsman Robert MacIntyre.
"I think this morning was probably the best golf I've played all week," he said. "This afternoon it just becomes a long day, you get a little bit sluggish and then you have to get back and Sergio is such a great match player... obviously very pleased to get on to Sunday."
Fleetwood, who aced the par-3 fourth in a morning win over South African 64th seed Dylan Frittelli, won the ninth on a 16-foot birdie putt and 11th with a par to go 2-up.
But Horschel birdied the par-5 12th after an approach to three feet and sank an eight-foot birdie putt at the par-3 17th to level the match, setting up the playoff.
Harman won seven consecutive holes with birdies to beat two-time Masters champion Bubba Watson in the morning and secure a berth in next month's Masters by reaching next week's world rankings top 50.
Kuchar birdied the par-3 fourth and seventh holes to seize the lead for good and rolled in a 10-footer at 17 to end the match.