Si Jiahui sent former champion Shaun Murphy crashing out of the UK Championship with a shock deciding frame victory on the opening day in York.
The 19-year-old, who dropped off the tour at the end of last season, received a place in the season’s first Triple Crown event as an amateur top-up and seized his opportunity by pulling off a memorable scalp.
Si stormed into a 5-1 lead with high breaks of 65 and 76, but only to miss a crucial blue and watch the 2008 UK Champion reel off four frames in a row with breaks of 60, 87 and 85 to force a decider.
However, roles were reversed as Murphy missed a costly blue in the decider, allowing Si to put the icing on the cake after making a 53 break earlier in the frame.
The defeat marks Murphy’s third consecutive First Round exit at the York Barbican.
Meanwhile, three-time UK Champion John Higgins avoided any such upset as he swept aside Michael Georgiou 6-1.
Higgins, who came into the event on the back of three straight defeats in televised finals, produced breaks of 60, 112, 55 and 134 in a dominant display.
Former world finalist Kyren Wilson coasted past Iran’s Soheil Vahedi 6-2 with high breaks of 71, 110 and 86.
World number 81 Ashley Hugill enjoyed a dream homecoming in York by defeating 2012 semi-finalist Mark Davis 6-4 with top breaks of 77, 79, 63 and 72.
Stephen Maguire, the 2004 UK Champion, safely saw off Sanderson Lam 6-3 with two century breaks along the way.
Tom Ford, semi-finalist here in 2018, thrashed Welshman Andrew Pagett 6-1 with high breaks of 89 and 77, while 2015 semi-finalist David Grace closed out a 6-2 win over Peter Devlin with a break of 104.
Dominic Dale will meet Si Jiahui in the Second Round after defeating Ashley Carty 6-4 with top breaks of 128 and 129 to his name.
Zhou Yuelong, semi-finalist 12 months ago, opened up with a 6-1 rout of Chinese compatriot Chen Zifan, as former World Championship semi-finalist Anthony McGill whitewashed 16-year-old Ukrainian Iulian Boiko.
18-year-old Wu Yize pulled off the biggest win of his career to date by knocking out last year’s semi-finalist Lu Ning 6-3 with a high break of 115.
Former Championship League winner Scott Donaldson suffered a shock 6-4 defeat to Pakistan’s Farakh Ajaib – who registered his first win in a ranking tournament this season.
UK Championship Snooker 2021 Day One Results
Tuesday November 23
Andrew Higginson 4-6 Mark Joyce
Anthony McGill 6-0 Iulian Boiko
David Grace 6-2 Peter Devlin
Zhou Yuelong 6-1 Chen Zifan
Kyren Wilson 6-2 Soheil Vahedi
Jak Jones 6-4 Oliver Lines
Lu Ning 3-6 Wu Yize
Dominic Dale 6-4 Ashley Carty
Scott Donaldson 4-6 Farakh Ajaib
Mark Davis 4-6 Ashley Hugill
Li Hang 6-3 Mitchell Mann
Tom Ford 6-1 Andrew Pagett
Stephen Maguire 6-3 Sanderson Lam
Chris Wakelin 6-2 Jamie Clarke
Shaun Murphy 5-6 Si Jiahui
John Higgins 6-1 Michael Georgiou