Ashley Hugill called his 3-2 victory over four-time ranking event winner Kyren Wilson at the British Open the biggest triumph of his career.
Wilson lost despite knocking in two century breaks – opening up with a 101 in the first frame before levelling things up at 2-2 with 115.
Hugill, who won a close second frame on the black and led after a break of 80, held his nerve in the decider and compiled a 57 under pressure to get himself over the line.
In the second round he will play Anthony Hamilton, who defeated Ukrainian Iulian Boiko 3-2.
Hugill told wst.tv: "It has to be the biggest win of my career – against the world number six, a really top player, and also my first one on the main TV table in a major tournament apart from the Shootout.
"I am very happy. I took confidence from my performances in the Championship League and went out knowing I couldn't back down or shy away.
"I am back to Sheffield tonight where I am based. In practice I am trying to play Yan Bingtao at least three times a week, and that is doing me good."
Shaun Murphy, Jack Lisowski and Anthony McGill were other top-16 casualties to follow Wilson out of the competition on Tuesday.
In a repeat of the World Championship final earlier this year, Murphy lost 3-2 to Mark Selby as he progressed in front of his home fans in Leicester.
Lisowski squandered a two-frame lead to lose 3-2 to veteran Barry Pinches, with the 51-year-old knocking in back-to-back breaks of 59 to win the match.
Perth’s Scott Donaldson defeated practice partner Dean Young 3-0 in a whitewash victory. Next up Donaldson faces Ben Hancorn, who registered a shock 3-2 defeat of Joe Perry. Ross Muir was also a 3-2 winner against Ryan Day.
Scotland’s Stephen Maguire defeated Jackson Page 3-0, while his compatriot McGill succumbed to a 3-1 loss against Zhao Jianbo.
Stephen Hendry is through after a 3-2 win against Chris Wakelin, while Mark Davis beat Michael Holt by the same scoreline. Ricky Walden also had to go the distance as he defeated James Cahill 3-2.
David Gilbert was a comprehensive 3-0 winner against Matthew Stevens and Hossein Vafaei is through after overcoming Jamie Jones 3-1.