Mark Williams booked his place in the World Championship quarter-finals at the Crucible in Sheffield with a 13-8 victory over Mark Selby.
Williams dominated early on against Selby
The Welshman, the 2000 and 2003 winner, dominated the first session to resume with a comfortable 11-5 lead.
Selby cut the gap to 11-7 with breaks of 90 and 71 and briefly entertained hopes of a comeback.
Williams closed on victory in the next, but Selby delayed him with a 73-0 frame before Williams clinched the win.
He now faces either fellow Welshman Ryan Day or Ronnie O'Sullivan in the last eight.
Williams said Selby's late comeback had forced him to work hard for the victory.
"Mark came out playing really well and put me under some pressure," said Williams.
"But I'm happy with how I handled myself and got over the line.
"I knew I wasn't home and dry at 11-5 and had a feeling he would come back because he had nothing to lose."
Selby said his slow start cost him the chance of a place in the quarter-finals.
"Mark deserved to win," admiited Selby.
"He was the better player and scored well.
"I gave myself a big target and if I had started the match the way I played in the evening session it could have been so different for me."
M Selby (Eng) 8-13 M Williams (Wal)
20-81 52-66 0-91 (73) 108-7 (57) 0-92 (64) 13-58 76-38 78-13 23-77 (63) 57-80 (74) 58-31 41-61 37-78 (54) 127-0 0-137 (137) 1-87 (78) 107-24 (90) 71-0 (71) 4-86 (85) 73-0 (65) 60-82