Mark Allen put up the fight of his life at the Crucible, battling back from 9-6 down to edge out Matthew Stevens 10-9 in a late night thriller.
Allen trailed 5-4 overnight and the Welshman won the first frame of the final session before the next four were shared.
Allen, who was receiving treatment for depression ahead of the World Championship, went 9-6 down before hitting a 103 break to peg it back to 9-7, then levelling at 9-9 to set up a dramatic deciding frame which the Ulsterman won to set up a clash with Barry Hawkins in the last 16.
John Higgins began what could be an emotional journey to a fourth Crucible title with a hint of early anxiety followed by a masterclass.
The champion of 1998, 2007 and 2009 looked to be carrying tension in his cueing arm in the opening stages of his clash with Stephen Lee, but three centuries after the mid-session interval showed why the Scot is the man they all fear this year.
He leads 6-3 overnight and will surely today book a clash with Rory McLeod, the 40-year-old coach of Qatar's national team who earned his place in the last 16 with an attritional 10-6 win over Ricky Walden.
Higgins made a greater impact on last year's World Championship after his shock second-round exit at the hands of Steve Davis, as he became caught up in a newspaper sting which not only thrust his name to the top of news bulletins but briefly put his career in jeopardy.
On the morning of the final, all the focus was on Higgins and the Scot was served with a six-month ban in September.
The punishment, backdated to May, was handed for breaching rules around betting, but the most serious charges relating to fixing frames in future matches were dropped.
Higgins has been warmly welcomed back to the tour, and since his return in November the 35-year-old has won an incredible five tournaments already — a European PTC event in Hamm, the UK Championship, Welsh Open, Hainan Classic and Scottish Professional Championship.
A sixth trophy could be less than a fortnight away, and what a moment that would provide.
Not only has he endured professional torment in the past 12 months, he also lost his father and biggest supporter, John senior, to cancer in February.
Higgins road-tested his form for the trip to Sheffield by routing Stephen Hendry 5-0 at the Scottish Championship last week and it is not only the bookies who make him the man to beat at the Crucible — his fellow Scotsman Graeme Dott sees it the same way.
“It's fair to say John Higgins would be favourite, because of the way he's been playing,” Dott said, after beating England’s Mark King 10-7.
Dott held off King to clinch a second-round match against Ali Carter.