Casey and Montgomerie will be Ryder Cup team-mates

Montgomerie could only manage a two-over-par 74 in the morning round and went to lunch five down.

The wayward Scot was unable to make any headway in the afternoon round and Casey finished the match off with a half at the 31st hole.

In the other semi-final, America's Shaun Micheel beat Swedish Ryder Cup player Robert Karlsson by two holes.

Highlights: World Match Play semi-finals

Interview: Paul Casey and Colin Montgomerie

Interview: Shaun Micheel and Robert Karlsson

It matched Montgomerie's biggest defeat in the event - he went down 6&5 to Ernie Els four years ago.

His deficit after the morning round could have been even bigger but for an 18-foot birdie putt to take the long 18th.

However, he drove into sand and lost the 21st, then could not match Casey's birdie at the 552-yard downhill 22nd as the Englishman went seven up.

Montgomerie hung on until the 31st hole, but a half gave Casey, who beat Canada's Mike Weir on Friday, another convincing victory.

This proves how good our [Ryder Cup] squad is. I look forward now to next week Colin Montgomerie

"I am very, very happy with that," Casey told BBC Sport.

"I didn't get the usual Colin Montgomerie today. For whatever reason he wasn't at his best.

"It's nice for me it finished early, it saves the legs and I wouldn't have liked to go down the stretch against him."

Montgomerie said: "I didn't get any breaks really, but that's like saying the fourth goal was offside when you have lost 6-0.

"This proves how good our [Ryder Cup] squad is. We have a fantastic squad and I look forward now to next week."

Montgomerie also took the opportunity to ask Europe's Ryder Cup skipper Ian Woosnam not to overburden Europe's players at the K Club.

"We must try and play around with the squad so that players don't play as many as five times as we have in the past," Montgomerie said.

Casey said: "It is important we stay fresh for the singles matches on the last day. I don't think there is any need to put guys out for all five matches."

Karlsson, like Casey a debutant at the event, went ahead after Micheel bogeyed the first and he doubled his lead with an eagle three at the fourth.

But former USPGA champion Micheel got back to all square with some solid golf and was one up after 18 holes.

Micheel moved two ahead with a birdie at 20 but Karlsson got back to all square with a scrappy bogey at 27.

It remained nip and tuck down the final stretch, with Micheel edging ahead again with a birdie at 33, and Karlsson had to hole a six foot putt at 35 to keep the game alive.

Micheel's approach at 36 ricocheted off the grandstand into a greenside bunker, but Karlsson was unable to take advantage and followed him in.

But Micheel got closer with his escape and when Karlsson missed his 15-footer, the Swede conceded the match.

World Match Play final tee-off times:
0915 and 1400: Paul Casey (12) v (15) Shaun Micheel