O'Sullivan, Robertson, Trump and Murphy reach World Championship last eight

Resuming 12-4 behind overnight from Sunday, Stevens made 63 to win the 17th frame, but with his neck obviously hurting O'Sullivan put him out of his misery with a winning run of 77.

"I built up a good lead so was happy just to come back for that," said O'Sullivan.

"When you have won it five times and won everything, you don't really get that excited. I am just happy to still be playing."

O'Sullivan made the second highest break of the tournament with a 139 on Sunday behind Neil Robertson's target of 143 before the Australian went two points better himself in ending Ali Carter's faint hopes.

Five-times champion O'Sullivan also rolled in three tons and six 50 plus breaks in a one-sided affair against Welshman Stevens, who has seen better days at the venue in reaching the 2000 and 2005 finals.

The UK champion O'Sullivan starts out his 17th quarter-final at the Sheffield venue against Stuart Bingham on Tuesday afternoon. 2010 winner Robertson was a 13-5 victor over Carter as he picked up the two frames he needed to progress having led 11-5 overnight.

For the second time in the tournament, Robertson made over 140. His 145 to finish off the match is a mark that is the highest so far after his earlier 143 had set the target.

2005 world champion Shaun Murphy continued his quest for a second Crucible title with a 13-5 win over fellow Englishman Joe Perry.

Masters champion Murphy will face qualifier Anthony McGill for a spot in the semi-finals over the best-of-25 frames on Tuesday and Wednesday, and will be wary of the Scottish rookie who conquered defending world champion Mark Selby in the last 16.

Rotherham's Murphy shared the spoils in two scrappy opening two frames against Perry in the opening session, but then hit his stride with a 121 in the third to go in front.

And he never looked back after that, adding breaks of 68 and 79 to make it 4-1, going 5-1 clear in the next as Perry missed on the green, then hitting a 54 to go 6-1 up.

"I am playing the best snooker of my life," he said.

"Being 12-5 in front is difficult to approach but I tried to prepare in exactly the same way as I would normally do and hope I got the chance to get over the line."

Perry shrugged off his desperation in the final frame of the session, but his break dried up on 66 - and Murphy cleared up to force a respotted black, before sinking a long effort to a baulk corner to complete a remarkable morning's snooker in leading 7-1.

He had increased that advantage to 12-4 on Sunday night with Perry winning the final frame of the evening to avoid defeat with a session to spare.

2011 finalist Judd Trump is also into the last eight after finalising a 13-8 win over Marco Fu having resumed 10-6 clear overnight that including a swashbuckling finishing run of 133.

"If I continue playing like that I will be tough to beat," said the 25-year-old.

"My game is there, it is just whether I can keep it up for the rest of the tournament."

Trump will meet China's number one player Ding Junhui in the quarter-finals with the first of two sessions in the last eight commencing at 10am on Tuesday morning alongside the first session of Murphy against Scotsman McGill.

Mark Selby (Eng) 9-13 Anthony McGill (Sco)

Joe Perry (Eng) 5-13 Shaun Murphy (Eng)

Barry Hawkins (Eng) 13-11 Mark Allen (NI)

Ali Carter (Eng) 5-13 Neil Robertson (Aus)

Ding Junhui (Chn) 13-9 John Higgins (Sco)

Marco Fu (HK) 8-13 Judd Trump (Eng)

Graeme Dott (Sco) 5-13 Stuart Bingham (Eng)

Matthew Stevens (Wal) 5-13 Ronnie O'Sullivan (Eng)

Anthony McGill (Sco) v Shaun Murphy (Eng)

Ding Junhui (Chn) v Judd Trump (Eng)

Barry Hawkins (Eng) v Neil Robertson (Aus)

Stuart Bingham (Eng) v Ronnie O'Sullivan (Eng)

Anthony McGill (Sco) v Shaun Murphy (Eng)

Ding Junhui (Chn) v Judd Trump (Eng