Three-time world snooker champion Mark Selby ended Australian Neil Robertson's hopes of a second world crown with a gritty 13 frames to 7 victory in their quarter-final at the Crucible Theatre on Tuesday.
English cuesman Selby reached his first world semi-final since 2017 -- the last time he won the title -- thanks to a no frills safety-first strategy that prevented Robertson from getting into his stride.
Selby had led 11-5 overnight and moved to within one frame of the last four by winning the first frame of the session.
Robertson, the champion in 2010, struck back with two successive frames but Selby confirmed his place in Wednesday's semi-final by winning the next.
Victory will be a huge boost to Selby who suffered a slump in morale following his 2017 world title and won only two tournaments in the next two years.
"Over the last 12 to 18 months I was questioning myself," said Selby.
"I had got so used to winning tournaments that when I wasn't winning tournaments it became very damaging to my confidence.
"I was happy with my performance against Neil.
"I felt if I got a chance I could score, and my safety play was back up with how it was a few years ago.
"As a match-play game it was right up there with my best performances.
"I can see the changes already, especially in my body language, so long may it continue."
Robertson paid tribute to Selby's safety play.
"Mark's defensive safety was absolutely unbelievable," said Robertson.
"He didn't let up really and I think he got his game plan spot-on over the two days."
Selby, 37, will play either another three-time world champion in Mark Williams or five-time champion Ronnie O'Sullivan.
Williams enters Tuesday's second session 6-2 up in the best of 25 frame contest against an opponent the 45-year-old Welshman has only beaten once in a ranking event in 18 years.
In the other quarter-finals, defending champion Judd Trump is in trouble in a grudge match with Kyren Wilson, who leads 10-6.
Qualifier Anthony McGill of Scotland looks favoured to meet the winner of that match as he leads Norwegian Kurt Maflin 10-6 going into Tuesday evening's final session.