Ronnie O’Sullivan is into the quarter-finals of the World Snooker Championship after a 13-7 win over Ryan Day at the Crucible.

The Rocket was not always firing on all cylinders, offering Day plenty of chances over the three sessions, but the Welshman continually spurned them.

The world number one was 5-3 ahead after Sunday morning’s first session and extended his lead to 10-6 in the evening, but appeared uncomfortable with how he was playing.

Day took the final frame of Sunday after O’Sullivan missed a straightforward red, which led to an angry swipe with his cue.

However, Dynamite was still not able to strike when opportunities arose on Monday, losing a close opening frame of the afternoon session.

The seven-time world champion then made an 85 to go one frame from victory, before Day stayed afloat by winning the 19th, but the Rocket got over the line in the next.

Next up for O’Sullivan will be either Stuart Bingham or Jack Lisowski, with the score standing at 9-7 in Bingham’s favour going into the final session on Monday night.

‘Yeah I kind of thought I battled really well in the safety department of that match, created loads of chances,’ Day told the BBC. ‘But struggling to settle all day, missed far too many balls when I was in amongst them myself. That’s something you can’t do no matter who you’re playing.’

O’Sullivan said: ‘I don’t know if it was comfortable, Ryan made it tough for me. I thought if I’d have not been as tight and clinical in some situations he’d probably have got on more of a roll at times. I was pleased to be able to stem that at times and try and have an impact when I got a chance.’

On the other table on Monday afternoon, Kyren Wilson made short work of finishing off Joe O’Connor, wrapping up a 13-6 win.

The Warrior has been in very impressive form so far at the Crucible, demolishing Dominic Dale in round one.

He now faces Mark Allen or John Higgins in the quarter-finals, with their heavyweight contest coming to a close on Monday evening.