Mark Williams became the oldest Crucible quarter-finalist for 15 years with a 13-10 victory over Hossein Vafaei at the Halo World Championship, setting up a potential clash with John Higgins.
Williams came to Sheffield with low expectations as he has had problems with his eyesight this season, and after losing 10-3 to Ding Junhui in his opening match at the recent Tour Championship he predicted he would be an "easy draw for anyone" at the Crucible. But after beating Wu Yize 10-8 in the first round, he impressed again against Vafaei, fending off a late fight-back to take the last two frames and rounding off the tie with a marvellous century.
Having turned 50 last month, the Welshman is the oldest quarter-finalist since a 52-year-old Steve Davis in 2010. It's a 12th appearance in the last eight for the Welshman and he continues to chase a fourth world title having lifted the trophy in 2000, 2003 and 2018.
If Higgins can convert a 12-11 lead over Xiao Guodong into victory tonight, then two of the all-time greats would clash on Tuesday and Wednesday. It would be a repeat of the 2018 final, which Williams won 18-16.
"I am praying that John will win tonight," said Williams. "It would be an incredible occasion, given the stage we are at in our careers. The reception would probably be like the Masters when we played in 2022 and we had a standing ovation. I would just love to play in that atmosphere again. Come on the old boys! The last few times I have come here, I am just trying to enjoy the moments because I don't know how many times I will be back. I don't know how I am still playing to a fairly decent level."
Trailing 9-7 going into the concluding session, Vafaei had a golden opportunity to narrow the gap in frame 17 but missed the final brown to a centre pocket leading 49-47, handing Williams the chance to pot brown, blue and pink for 10-7. Vafaei made a 70 clearance, from 52-1 down, to snatch the 18th and he led 57-26 in the next only for Williams to clear from the penultimate red for 11-8.
A run of 74 boosted Vafaei's hopes of a recovery. Williams led 35-0 in the next when he missed a red to a top corner, and Vafaei made 72 to close within one. Williams dominated the next for 12-10, and when Vafaei missed a red to a baulk corner early in the next, he wrapped it up superbly with 115.
"A lot of frames could have gone either way," added world number six Williams, who won the Champion of Champions earlier this season. "I made a lot of really good breaks. I missed easy ones too but that's what I do. When you miss an easy one you just have to get on with it. I made a fabulous break in the last frame. When I came to the table I thought if I could make 30 I would be in a good position, so to make a century was unbelievable."
Vafaei said: "It was very tight and tense. Neither of us played at our best. We were both tired. I am disappointed with my performance because I gifted him him many frames with my mistakes. I have to work more if I want this beautiful trophy. Mark will always be a tough opponent."
On the other table, seven-time Crucible king Ronnie O'Sullivan made a strong start to his second round tie with Pang Junxu, taking a 6-2 lead. O'Sullivan hadn't played competitively for over three months coming into this event, but after a 10-4 success against Ali Carter in round one he is now on track for a 23rd quarter-final which would extend his own record.
If O'Sullivan and Higgins join Williams in the last eight, it will be the fifth time that all three members of the 'Class of 92' have reached the quarter-finals in Sheffield - this previously happened in 1998, 1999, 2011 and 2022.
Breaks of 58, 91, 50 and 63 helped O'Sullivan build a 4-0 lead. China's Pang pulled one back with a 119 and had first chance in frame six but made only 33 and his opponent took it with a 68. Pang came from 52-0 down to snatch the seventh with runs of 34 and 32, but O'Sullivan took the last of the session to secure a four-frame overnight cushion. They resume on Sunday at 2.30pm.