Ben Curtis, who denied Thomas Bjorn the Open title in July, now blocks the Dane’s path to the final of the HSBC World Match Play final at Wentworth.
Bjorn today followed up his first round victory over Masters runner-up Len Mattiace by beating Masters champion Mike Weir by a convincing five and four margin.
Curtis, without a top 10 finish before or since his amazing out-of-the-blue triumph at Sandwich, defeated fellow American Chad Campbell five and three.
The other semi-final is the expected one between world number two Ernie Els, seeking a record-equalling fifth title, and number three Vijay Singh. But both had to work hard.
Els was five up with six to play on fellow South African Tim Clark, but lost the next four holes and survived on the last, while Singh was taken to the 38th before getting the better of US PGA champion Shaun Micheel.
Three months ago Bjorn led the Open by three strokes with four holes to play and then went bogey, double bogey, bogey and Curtis, 396th in the world at the time and 1,269th at the start of the year, became the unlikeliest holder of the claret jug in history. It was the first major he had ever played in.
But Bjorn was keen to play down talk of revenge.
“I don’t have any unfinished business with Ben Curtis at all,” said the Ryder Cup star. “It’s long gone for me – we’re in October now.
“I lost the Open and whoever I lost it to does not make any difference. I will be very determined to win, but that’s because when you look at the history this trophy is one you’d like to put your name on.”
Curtis commented: “I don’t think Thomas will be looking for revenge. He just wants to go out and win.
“This is a friendly tournament and I am sure it will be a friendly match.”
As for people possibly thinking he was a lucky winner at Royal St George’s Curtis said: “I know in my own heart that I totally deserved to win, but obviously you want to prove to everybody else that you deserve it.”
Weir never led Bjorn and was six down with 10 to play before mounting a mini-revival. He birdied the 27th and 29th and might have eagled the next had his opponent not conceded him the hole.
Having given himself a sniff of a chance, however, the Canadian left-hander extinguished his hopes with bogeys at the following two holes.
“I was very determined to put the pressure on Mike. You never feel in control against a player like him, but I didn’t make any big mistakes,” said Bjorn.
Curtis’ first competitive shot in Britain since his Open win was a shocker, a hooked drive that left him needing a three-wood to the green whereas others were hitting wedges and even sand-wedges.
He lost that and by the fourth was two down, but a superb inward half of 32, five under, took him ahead. The 11th, 12th and 17th were shared in birdies, but Curtis, having chipped in on the 17th, won the last with an eagle after a superb five-wood to 12 feet.
Campbell chipped in himself two holes later, but Curtis started making the crucial putts, going to the turn in 32 and adding another birdie at the 30th, where his opponent missed a four-footer.
After bogeying the 32nd by three-putting from off the green Campbell carved his next drive into trouble and conceded the hole before Curtis even reached the green.
Tee-off times in the semi-finals of the HSBC World Match Play Championship at the West Course, Wentworth, Surrey, England, on Saturday (all times Irish time, seeded positions in brackets):
0915 and 1345 (1) Ernie Els (Rsa) v (5) Vijay Singh (Fij)
0930 and 1400 (3) Ben Curtis (USA) v (10) Thomas Bjorn (Den)
Quarter-final results of the HSBC World Match Play Championship at the West Course, Wentworth, Surrey, England
(seeded positions in brackets):
(1) Ernie Els (Rsa) bt (9) Tim Clark (Rsa) 2 holes
(4) Shaun Micheel (USA) lost to (5) Vijay Singh (Fij) at 38th
(3) Ben Curtis (USA) bt (6) Chad Campbell (USA) 5 and 3
(2) Mike Weir (Can) lost to (10) Thomas Bjorn (Den) 5 and 4