Graeme McDowell today finally got the better of Nicolas Colsaerts in the Volvo World Match Play Championship, despite a remarkable escape from an unsavoury hazard by the defending champion.

Colsaerts beat McDowell in the final last year and also knocked him out in the quarter-finals in 2011, but the Northern Irishman made it third time lucky with a 2&1 win in the quarter-finals at Thracian Cliffs.

Three up after nine, McDowell seemed set to go further ahead when Colsaerts’ drive on the short par-four 10th finished inside a public toilet.

But after taking a penalty drop — bringing new meaning to the phrase ‘nearest point of relief’ — Colsaerts pitched onto the green and holed from 15ft for par to halve the hole.

Colsaerts could be heard laughing as he pleaded with the referee not to make him drop the ball inside a bathroom on live television, but had to drop it twice as it rolled nearer the hole the first time.

“I was laughing because I was going to look like a clown,” Colsaerts said. “I’m going to make ‘A Question of Sport’ and I’m sure it’s going to make the news, some Belgian dude dropping the ball in a toilet. It’s fun to be recognised for stupid stuff like that.”

After escaping with his par, Colsaerts got back into the match with a birdie on the 13th — where McDowell was going to drop at least one shot — and by winning the 14th with a par.

However, he missed a birdie putt from seven feet on the 16th to get back on level terms and then hit two clumsy pitches on the par-three 17th to allow McDowell to close out the win.

McDowell will face Branden Grace in the last four after he beat England's Chris Wood 2&1 in the quarter-finals, while the other semi-final sees another South African Thomas Aiken take on Thongchai Jaidee, two men who beat Ryder Cup star Ian Poulter in the group stages.

Aiken beat Italy's Francesco Molinari 3&2 while Jaidee defeated Scotland's Scott Jamieson 4&3.