Ronnie O’Sullivan showed signs of his best form as he took a 5-3 lead against Ryan Day at the World Championship.

Both players made a number of big breaks in a high-quality first session of their last-16 clash at the Crucible.

The 'Rocket' got off to a flying start, hitting a 123 break in the opening frame and following up with an 84 in the second to storm ahead.

Day quickly got a foot back in the match, replying with 74 and 78 to draw level after the first four frames, but O'Sullivan recomposed himself after the mid-session interval to restore his two-frame lead with breaks of 83 and 51.

The seventh frame saw Day reduce the deficit following a superb 115 on a difficult table before O'Sullivan quickly cleared 92 in the eighth. The pair will resume in the evening session on Sunday night.

Stephen Maguire secured his spot in the quarter-finals by beating Shaun Murphy 13-9.

The rivals have feuded for two decades following an incident where Maguire was penalised a frame for forgetting his chalk and the Scotsman held off a late fightback from Murphy to seal victory.

He resumed on Sunday morning with a 10-6 overnight lead and continued his quest to reach the last eight with a break of 68 before Murphy pulled a frame back.

Maguire then moved within one frame of victory but Murphy continued to battle, a 67 break earning him the following frame before he took the first after the mid-session interval to trail by three.

However, Maguire sealed victory in style, hitting the only century of the match with a 127 to set up a quarter-final meeting with David Gilbert.