John Higgins produced a resilient performance to recover from a 3-1 deficit and finish the opening session of his World Championship semi-final against Shaun Murphy at 4-4 in Sheffield.
On the other table, Wu Yize took a commanding 6-2 lead over Mark Allen in a session that was briefly interrupted by a power outage at the Crucible Theatre. Television coverage was disrupted for about 15 minutes midway through the third frame of the evening session, forcing the players to leave the arena until the issue was resolved.
Higgins, the 51-year-old four-time champion and the oldest semi-finalist since Ray Reardon in 1985, seemed to be feeling the effects of his late-night quarter-final victory over Neil Robertson. He struggled with easy pots in an error-prone display, but his trademark resolve saw him through.
Murphy, the 2005 world champion, looked in control after runs of 68, 69, and 100 gave him a 3-1 lead at the mid-session interval. However, the world number eight also made several loose shots, allowing Higgins to claw back with two scrappy frames to level at 3-3. Higgins then sealed the final frame with a break of 50 to ensure he was not behind after the opening session for the first time in this year's tournament.
In the evening session, Wu Yize impressed on his Crucible one-table debut, quickly settling with breaks of 77 and 55. Allen responded with a near-century, but the power outage disrupted his momentum. Wu then took control, firing breaks of 57, 78, and 64 to win three consecutive frames and build a 6-2 lead. Allen, appearing in his third semi-final in four years, was punished for a missed black in the final frame, allowing Wu to extend his advantage.
The best-of-33 encounters continue on Friday at 10:00 BST.