Mark Selby. Picture by Monique Limbos

DEFENDING champion Mark Selby dug deep with his back against the wall to win a thrilling final frame decider against John Higgins.

Selby came back from 5-3 behind to beat the four-times world champion and seal a Masters semi-final clash against Shaun Murphy.

In a tense quarter-final which never at one stage disappointed an enthralled Alexandra Palace crowd, Selby clinched victory with the scores deadlocked at 69-69 with a sensational double on the final blue which allowed him to force a potting position for the decisive pink into the middle pocket.

Selby clinched his fists with delight once the pink went in as his hopes of winning a fourth Masters title strengthened.

But Higgins will rue earlier missed opportunities to put the match to bed before Selby’s late brilliance.

In the penultimate frame Higgins had worked himself into a frame winning position but missed the final brown which allowed Selby the chance to level the match from 5-3 behind.

And in the final frame it was Higgins who had the early advantage but costly messed up his position when trying to get over the winning line and therefore missed a tricky red.

Top breaks of 70 and 98 helped Selby to a 3-1 lead at the end of the first session.

But in typical Higgins style, he battled his way back into the contest as a break of 69 and winning a frame on the final black helped him move in charge of the contest leading 5-3.

A break of 55 quickly halved Selby’s deficit before Higgins’ crucial miss on the final brown to the yellow pocket handed the world number two a huge reprieve and the golden chance to take the match into a decider.

Friday’s quarter-finals see reigning world champion Ronnie O’Sullivan face Ricky Walden (1.15pm) and world number one Neil Robertson takes on Stephen Maguire (7pm).