Mark Selby reached the last 32 of the Hong Rui Ma Yushan World Open in China with a 5-3 win against Elliot Slessor.
Selby, bidding to retain the world number one spot he has held since February 2015, was made to fight hard, letting slip a 3-1 lead before edging a scrappy eighth frame for victory.
He will now play Jamie Jones in the last 32, while Masters champion Mark Allen set up a clash with Jack Lisowski after cruising to a 5-1 win over Lyu Haotian.
World champion Mark Williams and Neil Robertson both registered 5-1 wins against Andy Lee and Alexander Ursenbacher respectively.
Ding Junhui overcame Chinese teenager Yuan Sijun 5-3 and Judd Trump, chasing his first ranking title for 10 months, won 5-1 against Martin O'Donnell.
Amateur James Cahill lost 5-4 to Andrew Higginson, who came from 4-1 down, while Kyren Wilson, China's Yan Bingtao and Michael Holt all progressed.