Snooker results: Ronnie O'Sullivan beats Mark Selby 10-7 in Shanghai Masters semi-finals

It was a match in which the momentum shifted throughout, but the decisive blow came in the 14th frame when O'Sullivan cleared the table with 66 to level at 7-7, Selby punished in brutal fashion having earlier left himself needing only a simple pink off its spot to move two frames clear.

Selby was visibly rocked by that body blow and O'Sullivan never looked back, reeling off the next three frames in double-quick time to book what will be the sixth Shanghai Masters final appearance of his illustrious career.

It took O'Sullivan a while to find his very best form, and the opening session was something of a struggle as he let slip a 2-0 lead to finish 5-4 in arrears after Selby signed off with breaks of 63, 101 and 99.

And Selby didn't play badly in the early part the concluding session, keeping O'Sullivan at arm's length thanks to further runs of 60, 54, 77 and 65, before the contest turned on a missed pink that may haunt the Leicester man for some time to come.

With just a scent of another comeback victory, as was the case when he came from behind 5-2 to beat John Higgins a day earlier, O'Sullivan sprung into life and finished with his vintage best.

A break of 69 allowed him to regain the lead for the first time since frame five and when he followed up with a silky 109, he had one foot over the winning line.

Another mistake from a now ragged Selby let O'Sullivan get his hand on the table once more in frame 17 and he added another century, his third of the match, clearing the table with a brilliant 118 to set up a meeting with either Neil Robertson or Luca Brecel.

O'Sullivan told WST: "The start of the match wasn’t so good. Until 6-5 and 6-6 I was struggling a bit. I tried to hang in there and made a little technical change.

"I thought I had to try something and find some form. I changed my alignment and my shoulder to get closed and more on line to control the white. It was difficult, but I was pleased to find some form at the end.

"I’ve learned so much over the years (on the mental side of the game), that I know what to do. It is just whether I can be bothered to do it all of the time. Sometimes it is hard to be giving 100% all of the time.

"I’ve been doing this for 40 years so you get tired and the motivation is not the same as when you are younger. I accept that and it does get harder to keep doing it."