By Clive Jones BBC Sport at Wembley

John Higgins 3-6 Mark Williams

Mark Williams eased to a 6-3 win over John Higgins to reach the semi-finals of the B&H Masters at Wembley Conference Centre on Friday.

The Welshman raced to a 5-1 lead, taking advantage of Higgins' nervy and inconsistent play.

But the Scot refused to buckle and replied with back-to-back centuries to claw his way back into the game at 5-3.

See Williams clinch his victory

Williams responded by downing a rare second century himself and killed off the match in style in the ninth frame.

The Welsh Open runner-up said he was not fazed by Higgins' late challenge.

"I knew he would come back at me when I reached 5-1," he said.

"I didn't get nervous, I felt comfortable and waited for my chance."

Higgins just could not cope with the fast pace of the table and missed several chances to steal the match.

My confidence is low at the moment and I just have to keep plugging away John Higgins

The Scot blamed a poor start against Williams for his slump in form.

"I missed a chance to go 2-1 up and just couldn't settle," said the 1999 champion.

"My confidence is low at the moment and I just have to keep plugging away."

But there were some quality strokes and the crowd enjoyed centuries from both players.

Williams reached a small landmark with his first in the fifth frame - it was his 150th century in competitive play.

"I don't get many centuries, " he admitted.

"Stephen Hendry has been giving me some stick but I've got five now and he's only got one."