Tiger Woods won a dramatic morning showdown with Rory McIlroy only to be upset by Denmark's Lucas Bjerregaard in quarter-finals of the WGC Match Play Championship.
Woods, a 14-time major champion seeking a fourth WGC Match Play title, defeated McIlroy 2&1 in a morning knockout match only to fall 1-up to the 50th-seeded Dane, dropping the 18th hole when he missed a four-foot par putt.
"We read it inside left center and it went left," Woods said. "It was just one of those weird spots. It's match play. They are going to put the pins in difficult spots and we just have to make the shots."
Bjerregaard, who will face US 23rd seed Matt Kuchar in a semi-final Sunday, marveled at his achievement and the crowds Woods drew to Austin (Texas) Country Club.
"We had a great match. It's a shame it had to end like this," Bjerregaard said. "I enjoyed playing with him. It was a cool experience. To say I've beaten Tiger, it's right up there.
"It's so different to what I've ever experienced before. I've never heard so many yells, his name all the way around. It was really enjoyable but it must be hard to do that every day."
Italy's Francesco Molinari, the highest remaining seed at seventh, will meet US 48th seed Kevin Kisner, last year's runner-up to Bubba Watson, in Sunday's other morning semi-final to set up an 18-hole afternoon championship final.
Bjerregaard, who also ousted Sweden's Henrik Stenson 3&2, opened with a 5-foot birdie then rallied after Woods answered with three consecutive birdies.
A bogey was enough for Woods to win the par-3 11th for a 1-up lead. Both birdied 12 and 13, then Bjerregaard missed long birdie putts to halve 14 and 15.
Bjerregaard sank a 29-foot eagle putt at the par-5 16th to level the match, then drained a 13-footer for birdie at the par-3 17th, forcing Woods to sink a tense six-footer for birdie to stay level as they reached the 18th.
"His ball flight was low and in these conditions that was advantageous," Woods said.
Woods chipped into a bunker but blasted out and, after Bjerregaard missed a birdie put to win, the 43-year-old American lipped out his last putt.
Woods, the 13th seed, never trailed in taking full advantage of McIlroy's struggles with the putter and a double-bogey disaster at the 16th hole as spectators roared.
"It was big for us inside the ropes too," Woods said. "It was fun for us. We battled hard against each other. I was fortunate to come out on top."
McIlroy, who had dropped only three holes in three matches, was 3-down after 10 against Woods but birdied to win 12 and 13 and looked to win 16 after Woods buried his tee shot under a bunker lip.
Instead, McIlroy followed a mammoth tee shot by finding a right rough slope, chipping over the green against a boundary mark, chipping again into a bunker and blasting out to two feet before surrendering the hole.
Woods holed a 13-footer to halve 17 and complete the victory.
"I played pretty consistent the entire day," Woods said. "I didn't give him any holes and Rory didnt make any putts. It was a tough day all around."
McIlroy, a four-time major champion, can complete a Career Grand Slam in two weeks by winning the Masters.
After his first match-play battle with his boyhood idol, McIlroy apologized on Instagram for exiting without talking to reporters and praised Woods for clutch putts late.
"Although I was disappointed with how the match ended, I showed real patience and persistence to claw a couple of holes back on the back nine, then squandered a great opportunity to get back to all square on 16," McIlroy wrote.
"Definitely one I let get away but I'll learn and move on."
Reigning British Open champion Molinari, Europe's Ryder Cup hero in last year's triumph over the US team in France, eliminated English 10th seed Paul Casey 5&4 and then beat US 57th seed Kevin Na 6&5.
Na, who had upset English second seed Justin Rose 2-up, began with a birdie but dropped the next six holes and never recovered.
"I just played very well from the start," Molinari said. "I made a lot of putts and didn't make too many mistakes."
Kisner routed China's Li Haotong 6&5 then edged South African 19th seed Louis Oosthuizen 2&1.
Kuchar, the 2013 winner, beat English 35th seed Tyrrell Hatton 4&3 and then beat Spanish 26th seed Sergio Garcia 2-up. The Spaniard birdied 15 and 16 to pull within 1-down but lost at 18.