Stuart Bingham produced a string of big breaks to turn his World Championship semi-final with Mark Selby on its head.
Bingham, trailing 9-7 after Friday’s morning session, played almost flawless snooker to win five successive frames with breaks of 131, 96, 78 and 68.
Selby dug in to take the next two but a 63 break earned Bingham a 13-11 overnight lead going into Saturday’s final session at 14:30 BST.
Kyren Wilson leads Shaun Murphy 10-6 in the other best-of-33 semi-final.
Wilson, 29, maintained his four-frame advantage during Friday’s afternoon session but Murphy produced an important late rally to keep himself in touch.
Last year’s losing finalist Wilson shook off the blow of losing a bizarre frame in which he conceded 53 penalty points to stretch his overnight 6-2 lead to 10-4 with a top run of 131.
But Murphy, 38, took the last two to close to 10-6, aided by breaks of 59 and a clearance of 86, to revive his hopes going into their final two sessions on Saturday (10:00 & 19:00 BST).