Qualifier Gary Wilson reached his first World Championship semi-final by beating two-time finalist Ali Carter 13-9 at The Crucible.
Carter surged into a 3-0 lead but Wilson hit back by taking five in a row and maintained his two-frame advantage at 9-7 after the second session.
The next four frames were shared, but Wilson coolly took the two he needed to secure victory.
Masters champion Judd Trump resumes 7-1 up against Stephen Maguire.
That means the Englishman could win with a session to spare over the Scot.
David Gilbert is 10-6 ahead against Kyren Wilson, while former champions John Higgins and Neil Robertson resumed on Wednesday morning tied at 4-4.