Summary O'Sullivan will now face either Barry Hawkins or Dominic Dale, with 2013 runner-up Hawkins.
LONDON (AFP) - Reigning champion Ronnie O Sullivan breezed into the World Championship semi-finals with a session to spare on Wednesday after completing a 13-3 win over Shaun Murphy.
Murphy made a strong start to their quarter-final on Tuesday by winning the first two frames, but O Sullivan roared back and won the next six frames to establish a 6-2 overnight lead.
The five-time champion stretched his advantage to 8-2 on Wednesday morning before 2005 champion Murphy clawed a frame back, but a break of 118 gave O Sullivan a 9-3 advantage at the mid-session break.
After a short delay due to a technical problem with the scoreboard, O Sullivan capitalised on a couple of routine misses by Murphy to close out victory.
He will now face either Barry Hawkins or Dominic Dale, with 2013 runner-up Hawkins 11-5 up in their contest at the Crucible Theatre in Sheffield, northern England.
Earlier, Mark Selby finished off a one-sided 13-5 win over Alan McManus to book his place in the last four.
Leading 12-4 overnight, the Leicester cueman needed only one frame to complete victory, but Scottish veteran McManus took the day s first frame thanks to a break of 69.
It proved only a stay of execution, however, and when McManus could not exploit his opportunities in the next frame, Selby pounced to set up a last-four meeting with either Judd Trump or Neil Robertson.
"I think it was four years ago since I was in the semi-final before, so it seems like forever with so many tournaments now during the season," Selby told BBC television.
"I m looking forward to it and can t wait to get out there."
Australian world number one Robertson made a poor start to his last-eight tie against England s Trump and was 6-2 down after the first session on Tuesday.
