Jack Lisowski edged out former finalist Ali Carter 10-9 in the first round of the World Snooker Championship at the Crucible.
Lisowski, the 14th seed, had fought back from 3-1 down to take a 5-4 lead overnight and it remained a tight contest through Tuesday's morning session.
Carter moved 8-6 ahead after the interval following a break of 72, only for Lisowski, who has reached three ranking event finals this season, to respond again as two half-centuries saw him level.
The 'Captain', beaten by Ronnie O'Sullivan in the final in 2008 and 2012, took a tense 17th frame, sinking a superb doubled red into the top-left pocket, as he moved within sight of victory.
However, 'Jackpot' Lisowski rallied again with a clearance of 82 to force the decider, with a break of 60 enough to take his place in the last-16, where he will play former champion Neil Robertson.
"It was a big win in there," said Lisowski, runner-up to good friend Judd Trump in the final of the World Grand Prix.
"I managed to hang on with a few frames, and at 8-6 it was not looking good for me, so to have won from there it was good stuff.
"In the tournament he was probably the worst draw out of everyone, but my attitude was 'it is the World Championship, it doesn't matter who you got because you have got to beat them all'.
"Next I have got Neil, so it just gets tougher - but if you want to win this thing, you have to beat everyone."
On the other table, world number 13 Mark Allen took a commanding 7-2 lead over China's Lyu Haotian, producing three centuries during the morning session.
Northern Ireland's Allen opened up with a clearance of 139, and continued his momentum until Lyu finally got on the board with a half-century break in the fifth frame.
Allen then reeled off another century before a break of 68 saw Lyu, ranked 56 in the world, pick up the seventh frame.
A further 116 break re-established Allen's superiority, before a clearance of 69 put him within touching distance of the second round. The match will conclude on Tuesday evening.
Judd Trump made an emphatic start to his quest for a second world snooker title as he established a 7-2 overnight lead over Liam Highfield.
Trump, the dominant force on this season's tour with five titles already to his name, kicked off with a break of 116 and seldom looked back as qualifier Highfield struggled to stay in touch.
Questions had been raised about Trump's tag as title favourite after uncharacteristic early defeats in the Players' Championship and Tour Championship respectively.
And while he did summon a series of errors, including missing a black off its spot, his opponent could not capitalise and Trump sailed into a 3-0 lead.
Highfield did eventually get on the board but Trump restored his three-frame advantage with a break of 75 then overturned a deficit of 50 points in the next to go 5-1 up.
Highfield, who made his only previous appearance at the Crucible in 2018, responded with a gutsy 77 but Trump finished the session in style, including a knock of 86, ahead of Tuesday's conclusion.