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.
More to follow.