Kyren Wilson maintained a healthy five-frame lead over Jak Jones as he moved to within three frames of his first world title, leading 15-10 going into the final session.
The Englishman, 32, who is appearing in his second final, made three half-century breaks and crucially won the last frame of the session to keep his determined Welsh opponent at bay.
Jones, who is aiming to become the first qualifier to win the trophy since Shaun Murphy in 2005, had trailed 11-6 overnight but twice cut his deficit to just three frames, at 11-8 and 13-10.
The best-of-35 encounter concludes from 19:00 BST, with a maximum of 10 more frames to be played live on BBC Two.
Dramatically losing a seemingly pivotal final frame on Sunday on the black had left Jones needing to make the biggest final-day comeback in Crucible history to triumph.
But far from suffering any hangover, Jones, who has spent 22 hours more than Wilson at the table en route to the final, set about his task in determined fashion.
A wonderful long red was the precursor to a break of 64 for the world number 44 in Monday’s opening frame.
A break of 59 in the next – after bravely taking on a difficult red into the left middle pocket – followed as he reduced his arrears to 11-8 in a frame that included a short delay when a member of the audience was taken ill.
Wilson took the 20th frame with timely half-century and punished a loose break-off shot by Jones in the next, making 83 after the white caught the blue on the way back to baulk.
With the crowd willing Jones on he responded, crafting breaks 90 and 73 to again claw himself back to within three frames at 13-10.
But Wilson, who is looking to join a list including the likes of Mark Williams, Mark Selby and Judd Trump by winning a world final at the second attempt, held his nerve to go 14-10 clear with an 87.
And the world number 12 then took the final frame of the afternoon – after Jones missed a black off its spot and a yellow to the middle pocket – to draw the session and move even closer to fulfilling his greatest ambition
