John Higgins fought back from one of the worst Crucible sessions of his career to keep his dream of winning a fifth World Championship title alive at the Crucible.
Higgins was in desperate form for much of the morning session against David Gilbert, but went on to score a tournament-high break of 143 as he reduced the overnight deficit to 13-11.
It was a gutsy performance from Higgins after Gilbert had started the day by winning three straight frames – including a break of 125 in the opener – to turn a 5-3 lead from the first session into an 8-3 advantage.
But for a missed green in the next it could have been 9-3, but Higgins characteristically dug deep to win the next two and haul himself back into contention.
The Tamworth player responded magnificently, with a break of 72 winning the penultimate frame and a nerveless final black sealing a 10-6 advantage ahead of their return for the evening session.
The evening’s action began in bizarre fashion when the referee ordered a member of the audience to leave for apparently shouting something following the initial break-off shot.
Gilbert continued to show few signs of nerves as he extended his lead to five frames by taking the opener.
Higgins, who still seemed far from top form, pulled one back after a lengthy safety battle and, after Gilbert won the next with a 75, the Scot brilliantly cleared the colours to reduce the deficit again to 12-8.
Higgins’ stunning clearance of 143 also saw the tournament reach 86 centuries for the fortnight, equalling the record.
Gilbert appeared unfazed and responded immediately with a break of 91 to re-establish his four-frame lead.
But the underdog’s nerves were clearly on show in the final two frames of the session, which Higgins battled through to win and reduce the deficit to 13-11 going into Saturday afternoon’s concluding session.
The nerves were on show no more so than during the below shot, where Gilbert completely missed every ball and sent the white ball into the pocket.
It certainly gives Gary Wilson a run for his money in the worst shot competition.
In the other semi-final, Judd Trump will take a 9-7 advantage into the concluding sessions of his semi-final against qualifier Wilson.
Resuming at 4-4, Wilson twice nudged in front before Trump, looking to reach his first final since he lost to Higgins in 2011, showed signs of stirring with a break of 73.
While Wilson continued to look far from overawed by the big occasion, he was rendered a virtual spectator as Trump reeled off the next four frames in succession to seize control.
But just when the momentum appeared to have shifted in favour of his opponent, Wilson responded again, scoring an excellent 77 break in the final frame of the day to reduce the deficit.
Trump and Wilson are set to play to a finish over two sessions on Saturday, sandwiching the conclusion of the clash between Higgins and Gilbert in the afternoon.