Giant-killer Jak Jones came from 3-0 down to level at 4-4 against Stuart Bingham in the first session of their Cazoo World Championship semi-final battle.
The session turned on a missed blue from Bingham in frame four when he had the chance to go 4-0 ahead, allowing Jones to gain a foothold and eventually fight back to all square. They play three more sessions on Friday and Saturday, with first to 17 frames to go through to the final to meet Kyren Wilson or David Gilbert.
World number 44 Jones is playing in the Crucible semi-finals for the first time and aiming to become the lowest ranked champion since Shaun Murphy who was 48th in 2005. The 30-year-old Welshman has already knocked out Zhang Anda, Si Jiahui and Judd Trump to reach the last four of a ranking event for only the second time in his career.
Basildon's Bingham lifted the trophy in 2015 and hopes to become only the seventh player to conquer the Crucible more than once, after Steve Davis, Stephen Hendry, Mark Williams, Ronnie O'Sullivan, John Higgins and Mark Selby. The 47-year-old, who beat O'Sullivan on Wednesday night, is competing in his third Sheffield semi-final.
Bingham took the opening frame with a break of 76, then in the second he made 94 after Jones had missed a red to a top corner on 27. In frame three, Bingham led 49-36 when he trapped his opponent in a snooker on the last red, and from the chance that followed he went 3-0 ahead. He was on the verge of extending his lead when he missed the blue off its spot in frame four, leading by 37 points with two reds left. Jones made a fantastic 40 clearance, pulling off a series of difficult pots, then cupped his ear to the crowd as they applauded his resilience.
In the fifth, Bingham had first chance but ran out of position on 20, and a thumping long red from Jones set him up for 66 to close to 3-2. Soon the Cwmbran cueman was level as he won a safety battle on the last red in frame six and took advantage.
Bingham made a superb 79 clearance in the seventh after Jones had missed the blue to a baulk corner when he led 44-1. In the last of the session, Bingham was on 15 when he missed a tricky black to a centre pocket, and Jones responded with 72 for 4-4. The duo will be back on the stage at 2.30pm on Friday.