Stephen Maguire defeated reigning champion John Higgins 6-4 to set up a UK Championship quarter-final meeting with Judd Trump.
Maguire lost just one of the opening six frames to lead 5-1, before Higgins fought back with breaks of 101, 54 and 95 to pull it back to 5-4.
But 2004 winner Maguire held his nerve to win the 10th and take the match.
Neil Robertson overcame Graeme Dott 6-3 in the other of the evening's second round matches.
The Australian former world champion will play Ding Junhui in Thursday's quarter-final.
But the stand-out performance of the night came from Maguire, who compiled a tournament-high 144 break in frame two as he raced into a 3-0 lead.
Higgins clawed a frame back before the interval with a battling break of 60, but a typically aggressive Maguire extended his lead to 4-1 in the fifth, capitalising on a missed black by Higgins to put on 57 and take the frame.
And Maguire was on the brink of victory after extending his lead with a break of 66 in frame six.
But four-time world champion Higgins fought back with a superb century to keep his tournament alive and followed it up with classy breaks in frames eight and nine to pull it back to 5-4.
Maguire then capitalised after Higgins missed a straightforward black in the ninth frame to win the match and set up a meeting with 22-year-old Trump, who defeated Ronnie O'Sullivan earlier in the day.
On the other table at York's Barbican Centre, Robertson prevailed in a cagey affair in which he was never behind.
The 2010 world champion won the first frame but Dott hit straight back to level, clinching a tight second frame on a re-spotted black.
Robertson then came from behind to re-take the lead, narrowly winning the fourth before Dott replied to win a scrappy 36-minute fifth frame.
Robertson won the next two frames and looked to be in control of the eighth, but Dott battled back to take it on another re-spotted black and set up a tense finale.
The Scot then raced ahead in the following frame with a cool break of 66, but Robertson replied with a superb 68 to seal the victory.