Ronnie O’Sullivan admitted he was surprised with the “easy” nature of his victory as he demolished Shaun Murphy to reach the semi-finals of the World Snooker Championship yesterday.

The defending champion completed a 13-3 win with a session to spare as he capitalised on a host of mistakes from his opponent and will go on to face Barry Hawkins or Dominic Dale in the last four.

“You just never know what type of match you’re going to get,” O’Sullivan said.

“You can expect a really tough match and it turn out easy like it did with Shaun. I didn’t expect to win it that easy to be fair. He’s a free-scoring great potter.

“He just missed a few balls and let me in quite easily. I still had to pot them but I didn’t have to fight for my chances.”

O’Sullivan claimed seven of the eight frames yesterday after overcoming an early 2-0 deficit to lead 6-2 overnight.

The five-time champion added the opening two in the morning to stretch his advantage before Murphy got a frame back in the 11th but O’Sullivan followed that with a break of 118 to take a 9-3 lead into the mid-session interval.

The restart was delayed for a short while due to a problem with the scoreboard and when play resumed O’Sullivan made a break of 59 before giving Murphy a glimmer of hope.

A missed green off the spot in the final frame summed up Murphy’s performance as five-time champion O’Sullivan again capitalised, closing out a comprehensive victory with the minimum of fuss.

Six-time Crucible victor Steve Davis claimed Murphy had let an opportunity slip through his fingers after the match, saying: “At two-nil Ronnie looked very shaky. He played a great snooker that Shaun failed to get out of, and from then the whole game swung around and Shaun effectively collapsed.”

But Murphy insisted that was not the case and he was just the latest victim of O’Sullivan’s brilliance.

“I knew it was going to be a challenge,” said Murphy.