SHEFFIELD, England - China's former world number one Ding Junhui took a 6-3 lead over Anthony McGill of Scotland in the opening day's snooker world championship at the Crucible Theatre here on Saturday.

Ding, ranked 10th in the world, pulled ahead 4-1 with breaks of 64 and 70. World number 24 McGill, who was crushed last year here by Ding 13-4 in the second round, won the next frame 73-57 but Ding made a break of 129 points in the seventh frame and took the eighth easily for a 6-2 lead.

McGill gave the Chinese super star no chance in the ninth with a break of 76 to make it 6-3 after the first session.

Ding, the 2016 runner-up, will resume the competition with the Scot on Sunday morning and look to reach the second round at Crucible for the 10th time.

Ding's compatriot Tian Pengfei, ranked 81st in the world, took a surprise 5-4 lead over 15th-ranked Stephen Maguire of Scotland.

Tian, one of six Chinese players in the field this year, took the opening frame with a break of 52. Maguire levelled with a run of 80 then took a scrappy third frame, before Tian made it 2-2 with a 59.

In frame five, Maguire came from 58-0 down to take it with a clinical 62 clearance, then he added the sixth for 4-2. But Tian rose to the occasion as the session progressed, winning the last three frames with runs of 45, 100 and 70. They resume on Sunday at 7pm.

Defending champion Mark Williams fought off a Martin Gould fightback with a 10-7 win.

Gould pegged Williams back from 9-4 to 9-7, before the Welshman eventually managed to get himself over the line and book a second round meeting with either David Gilbert or Joe Perry.

Williams, who also lifted the trophy in 2000 and 2003, said, "It was a tough first round match and I thought I played quite well.

"I just think my form has been improving for the last month or two and it showed there. Even though the last few frames were a bit scrappy, overall it was good."

In the day's other matches, 2010 champion Neil Robertson of Australia stormed to a 9-0 lead over Michael Georgiou of Cyprus. World number 14 seed Luca Brecel of Belgium fought back from 3-2 down to lead England's Gary Wilson 5-4.