Ryan Day fought back from 3-0 down to knock former champion Ding Junhui out of the Dafabet Masters on Monday.
World number four Ding, winner in 2011, had breaks of 111 and 58 in his fast start at Alexandra Palace but centuries in the fifth, sixth and 10th frames secured an impressive 6-4 win for the world number 17 from Wales.
Ding follows Mark Selby out of the competition, with the reigning world champion beaten by Mark Williams on Sunday.
World number three Judd Trump had to hold off a fightback to claim his place in the quarter-finals.
Trump led 5-1 against Liang Wenbo, who rallied with back-to-back centuries before eventually losing 6-4.
Trump is the 4/1 second-favourite in Sky Bet's outright odds for the Masters.
Liang, ranked 19th in the world, was on course for a 147 in the second frame before missing the 11th red, but then sat and watched Trump reel off the next four frames.
Liang hit back with two half-century breaks in the seventh frame, a tournament-high 139 in the next and 116 in the ninth to pull within one frame, but Trump got over the line thanks to a break of 85.
Dafabet Masters Daily Schedule & Results
All matches up to and including semi-finals are best of 11; final is best of 19
Sunday January 14
- Mark Selby 5-6 Mark Williams
- Mark Allen 6-2 Luca Brecel
Monday January 15
- Ding Junhui 4-6 Ryan Day
- Judd Trump 6-4 Liang Wenbo
Tuesday January 16
- Ronnie O'Sullivan v Marco Fu (1300)
- Barry Hawkins v Kyren Wilson (1900)
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