Alan McManus trailed Ding Junhui 14-10 last night in the other semi-final.
Fu had started yesterday trailing 5-3 but outplayed the world number one and was looking to take the lead in the 15th frame when the unthinkable happened.
While chalking his cue and glancing at the table mid-break, Fu nudged the tip off and joined the Crucible crowd in shock as he realised what had happened.
BBC analysts Stephen Hendry and Steve Davis, owners of a combined 13 world titles, suggested the incident could upset Fu’s progress in the best-of-33 encounter.
However, after an interlude for running repairs, Fu showed no concerns with his amended equipment and closed out the frame with a break of 81.
Selby, who had been short of his best throughout, won the last to ensure they would resume this morning with nothing between them, but not before both made big errors.
Fu looked to have it won before he botched the final red, a mistake his rival then matched before a sloppy safety from Fu finally settled matters in Selby’s favour.
He finished with a break of 81, his best of the day compared to two centuries from Fu, who made 135 and 114. The match continues at 10am.