Neil Robertson has endured a mixed night at the World Snooker Championship, the Australian hitting a 147 break but losing a last-frame decider to Jack Lisowski.
The 14th seed went into the final session holding a 9-7 lead, but Robertson, the 2010 champion, was able to get back to 10-10, helped by a maximum in the 19th frame.
While Robertson did not have to navigate too many issues in compiling just the 12th 147 at the Crucible, it was a classy feat on the back of his struggles earlier in the contest.
However, having watched Robertson lead 11-10 and 12-11, Lisowski battled his way to the final two frames, the decider being locked at 18-18 before the 30-year-old held his nerve to set up a meeting with John Higgins.
In the other match of the evening session, Judd Trump booked his place in the last eight with a 13-11 victory over Scotland's Anthony McGill.
At one stage, Trump found himself 11-7 ahead and two frames from the win, but McGill reeled off four of the next five to keep himself in the contest.
However, Trump managed to get over the line in the penultimate frame, setting up a showdown with Stuart Bingham.