Jamie Jones became the third Welsh player to reach the Betfred.com World Championships quarter-finals when he beat Andrew Higginson 13-10.
Jones, the current world number 36, had put out former champion Shaun Murphy in the first round and will now play Ali Carter in the last eight.
The Welsh qualifier, 24, had led 10-6 overnight but Widnes cueman Higginson stunned him by winning the first four frames of Monday's evening session to level the match.
However, the Neath potter regained his composure and won the next three - sealing the match with a 135 break.
Jones said: "I feel relief. I've played Ali before and I won it so hopefully that's a good omen."
"I love playing at the Crucible. I have surprised myself really, I came up here playing pretty well but I didn't think I would handle the Crucible as well as I have done. To win two games here on your debut is pretty good I think."
Higginson said: "All credit goes to Jamie, but I'm disappointed. I've enjoyed my time here and you get a feel for the place."
