John Higgins upset the form book to lead title-holder Mark Selby 10-7 in the World Championship final on Sunday.
Selby, bidding to win his third world title, found himself 6-2 down against four-time champion Higgins come the end of the first session at the Crucible Theatre in Sheffield, northern England.
But with the showpiece match a best of 35 frames contest, comebacks from large early deficits are possible -- as Dennis Taylor proved when recovering from 8-0 down to beat Steve Davis in a black-ball finish in the last frame of the 1985 final.
And Selby, perhaps the toughest match-player in the game today, duly fought back, with the Englishman winning the final three of the day in a match that will be played to a finish on Monday.
Nevertheless, it was still an impressive start from the 41-year-old Higgins, bidding to become the oldest world champion since snooker great Ray Reardon won the last of his six titles aged 45 in 1978.
The Scot, playing his first world final since he beat Judd Trump six years ago, was quickly into his stride and a break of 141 in the fourth frame saw Higgins displaying all his old class.
Contributions of 63 and 95 put Higgins 4-2 up and he ended the session by edging a tight eighth frame.
Higgins was 10-4 up at one stage but Selby, belying his previous poor form, hit back with breaks of 81 and 121 before winning Sunday's final frame for good measure.
Prior to the final, Higgins suggested Selby could top Stephen Hendry's modern-day record of seven world titles, with time on the 33-year-old Englishman's side.
"He could be the one right now who could challenge Hendry's seven titles," Higgins said.
"If he goes ahead and beats me, it'd be his third and he's still a young man."
Higgins was, however, quietly confident of his own chances, saying: "I'm very proud to be in my sixth world final, and it's a great feeling to be going for my fifth world title."
The pair met in the 2007 world final, with Higgins winning 18-13 against a 23-year-old Selby who unexpectedly came all the way through from the qualifying event.
"After that tournament I told him, 'I know you're disappointed but don't be because you're definitely going to come back and win this thing'," Higgins said.
"He's proven that, and now he's going for his third one and he's going to maybe be emulating Steve Davis and Stephen Hendry by retaining it. He's a special player."