Ding Junhui and Ronnie O'Sullivan all-square after mesmerising opening session

Ding Junhui and Ronnie O'Sullivan produced a potting masterclass as they went toe-to-toe in their Betfred World Championship quarter-final at the Crucible .

Every frame saw a break of 50 or more as Ding raced into a 3-0 lead but O'Sullivan responded by taking the next three before the pair split the last two to go into this evening's session all-square at 4-4 in Sheffield.

Ding took the opening frame courtesy of a 71 break and then followed that up with a magnificent 128 clearance to double his advantage. It got better for the world number four as another run of 71 put him further ahead with O'Sullivan barely getting to the table.

But the 41-year-old hit back with a 63 break to finally get on the scoreboard before the mid-session interval and took the first after the restart with a run of 99 to close the gap to within one frame.

A 65 break from O'Sullivan sealed the sixth to level the match but Ding stopped the rot by scraping the next via a re-spotted black despite a 69 break from the five-time world champion, who finished off with a run of 59 to restore parity.

On the other table, John Higgins nudged ahead in his last-eight clash with Kyren Wilson as he took a 5-3 lead into the evening session.

Higgins dominated the opener before a break of 60 in the next frame put the Scot 2-0 ahead, but Wilson responded by winning the tactical battle in the third frame and soon levelled the match with a run of 92.

A lengthy fifth frame went the way of Higgins to retake the lead with Wilson levelling the scores with a break of 61 before there was a 15-minute delay for the Englishman to repair a broken tip, which affected the 25-year-old as the world number six took the final two frames.