This was not how Ronnie O'Sullivan had pictured things. Despite playing at a high level for long stretches after his 6-2 lead, he could only watch as his 9-4 advantage was whittled down to 9-7.
John Higgins dug deep at the end of the session and, with a bit of luck, fought his way into a promising position ahead of the final session, which takes place tomorrow afternoon.
Both players started nervously, with O'Sullivan missing a straightforward pot after scoring 21 points. Higgins took advantage to make 32, but then lost position on a red. After a safety exchange, the Scot got another chance and secured the frame with an 83 break.
Ronnie O'Sullivan makes John Higgins look second best
O'Sullivan was unfazed: a sensational shot-to-nothing red got him going, and he completed a break of 116. In the eleventh frame, he capitalised on a lapse in concentration from Higgins, who left a simple red, paving the way for an 80 break from O'Sullivan. Higgins responded before the interval with a 55, reducing the deficit to 4-8.
O'Sullivan continued to dictate play after the mid-session interval. Higgins missed a long red, opening the table for O'Sullivan, who rattled off 91 points in quick succession to move 9-4 ahead.
John Higgins fights his way back
But Higgins refused to give in and gradually worked his way back into the match. In the 14th frame, he started with a 71 before snookering himself on a red. O'Sullivan, needing a snooker, battled back and even forced the necessary foul points.
In a tense colours battle, with most balls off their spots, he lost position on the green. O'Sullivan left the ball hanging over the pocket, which Higgins gratefully accepted to secure the frame.
O'Sullivan could have taken the next frame too, but after a 55 break, he missed a red. Higgins mounted a comeback with two smaller breaks and, on the final black, completed the turnaround to close to 6-9.
O'Sullivan vents his frustration
The final frame of the evening was full of drama. O'Sullivan missed two straightforward pots and showed his frustration by thumping the table with his fist. Higgins seemed to have everything under control, but after 39 points, the cue ball went in-off into the middle pocket after potting a red.
O'Sullivan, with ball in hand, constructed a 53 break but missed the last red. After a brief tactical exchange, Higgins got a chance but also missed narrowly.
The red stayed close to the corner pocket, but Higgins left the cue ball in such a way that O'Sullivan could only reach it with a swerve shot. The record world champion managed it, but both the red and cue ball ended up in the pocket.
Higgins didn't let the golden opportunity slip in the colours battle and won his third frame in a row, reducing the 2-6 deficit from the first session to 7-9.
Mark Selby forced to chase the game
On the other table, big breaks were few and far between. Mark Selby and Wu Yize engaged in tactical battle after tactical battle, with Wu surprisingly often coming out on top. He takes a 9-7 lead into tomorrow, after the session had started level.
The very first frame was a tense affair. With several small breaks, neither player could pull away, so a safety exchange on the brown proved decisive. Wu went for a long pot, missed narrowly, and Selby cleared up to the pink to take the frame. The 10th frame was also closely contested, with Wu holding off Selby's snooker attempts to level at 5-5.
Mark Selby: Uncharacteristic errors cost him frames
The next frame was far less dramatic: Wu used a series of small breaks to pull clear and lead 6-5. The twelfth frame proved a turning point for Selby. Wu built a comfortable lead with a 56 break, but let Selby back to the table before the frame was safe.
The 'Jester from Leicester' fought back and had done the hard work, only to miss a relatively simple yellow off the spot in the colours. Soon after, he trailed 5-7 at the mid-session interval.
Selby quickly reduced the gap to 6-7 after the break, but then lost another frame in dramatic fashion. The four-time world champion built a 67:0 lead, but lost position on the frame ball. Wu staged a remarkable comeback, clearing with a 71 to steal the frame on the final black.
Mark Selby stays in contention
The 15th frame was again a scrappy affair, but Wu eventually built an unassailable lead without needing snookers. Selby gave everything in the colours, but couldn't force the necessary fouls and slipped 6-9 behind.
At least Selby got in first in the final frame of the session, making 45 before a split went wrong. Wu couldn't take advantage, and Selby punished him with an 81 to comfortably close to 7-9. The decider between the two will come tomorrow afternoon.