Victor Dubuisson held off Graeme McDowell to set up a semi-final clash with Ernie Els as the Frenchman’s dream WGC-Accenture Match Play Championship debut continued in Arizona.
McDowell had not held the lead on a tee all week as he produced stunning comeback victories against Gary Woodland, Hideki Matsuyama and Hunter Mahan, but Dubuisson made brave up-and-downs at the 17th and 18th to hold on to the one up advantage he secured when his opponent three-putted the 16th.
The Northern Irishman had led for the first time at Dove Mountain when he eagled the long second and went two up at the next with a birdie.
Dubuisson, who in contrast had not trailed in the first three rounds, won the fourth and seventh then chipped in at the ninth to get his nose in front.
McDowell took the 11th and 13th to twice square the contest either side of a Dubuisson birdie at the 12th, but for once the former US Open Champion could produce no fireworks over the closing holes, a missed putt from 20 feet at the last sealing the Turkish Airlines Open winner’s progress.
Dubuisson now faces Els as the two remaining European Tour Member’s compete for a place in Sunday afternoon’s final, whilst in the other semi-final Rickie Fowler goes up against Australian Jason Day.
“I played well today,” said Dubuisson. “I knew Graeme was going to be a tough player to beat, but I just played my own stroke play and I didn't watch him too much.
“[Winning in Turkey] gave me some confidence to win, but you always want more and more.”
Speaking about facing a four-time Major Champion in the semi-finals, the 23 year old added: “I know he's a great guy, very nice man, but I've never played with him before. He has a lot of experience.
“He has won so many tournaments and Majors, and I will just do the same as I did today and yesterday against Bubba and Graeme, just play my own stroke play and don't watch him, don't be impressed.”
Louis Oosthuizen received lengthy treatment for a long-standing back injury before play started and needed more out on the course before eventually losing 2 and 1 to Day, who reached the last four for the second year running.
Former Open Champion Oosthuizen looked to be in real trouble from the outset as he carved his opening tee shot into the desert. After attempting to hack clear from a bush, the South African quickly conceded the hole and seemed likely to fall two down after another errant drive on the second.
However, this time Oosthuizen took a penalty drop and then hit a superb third shot with a fairway wood on to the green, holing the putt from 20 feet for an unlikely winning birdie.
Another birdie on the third briefly took Oosthuizen one up, but he made a mess of the fourth with two bad pitches and went behind to a Day birdie on the fifth.
Day won the ninth and 11th to move three up, but Oosthuizen continued to battle hard, winning the 13th and halving the 14th and 15th with birdies, but Day held on to seal victory.
Elsewhere, Rickie Fowler prevailed in a topsy-turvy encounter with compatriot Jim Furyk.
Furyk produced a brilliant turnaround after Fowler went three up on the 11th.
However, Furyk then birdied the 13th, 14th and 15th and won the 16th with a par to move one ahead with two to play.
But in a remarkable twist it was Fowler who won the 17th and 18th with pars to progress to face Day.
Fowler will take on Day in Sunday morning's semi-final, who admitted he was wary of Oosthuizen despite the obvious injury problem.
Day said: "It's that old saying, beware of the wounded golfer. I think he went out the last four days with no expectations and I think that's why he's playing so great. I wanted to play good myself and get through to the next day.
"I love the golf course and I just like that one-on-one match. It's fun fighting it out to see who's best."
Oosthuizen added: "I was disappointed to start on the range this morning not feeling too good. It got better, the last four or five holes I felt I could get through the ball better. It's a bit painful that it always happens when I'm playing well and I need to address it big time and get it sorted.
"I felt I played really well but you can't give away holes to a guy like Jason. I had a tough start and it was really tough to get back from that."
