The 33-year-old Scot had played magnificently to overwhelm Ali Carter 5-0 with two century breaks less than 24 hours earlier.

But he could not reproduce anything like that form today as Gray notched five consecutive frames to qualify for his first ever appearance in the last four of a ranking event.

‘‘I’ve not played as badly as that since losing to Anthony Davies in the British Open last October,’’ admitted Hendry. ‘‘I don’t know where that performance came from.

‘‘The tournament was there to be won and I can’t believe I’m sat here having lost.

‘‘I am playing well in practice, but that doesn’t give you the right to win matches. When it came scrappy my focus wasn’t there.

‘‘Generally my game is good, but there is a lot of work to be done before I get to Sheffield.’’

World number five Hendry meets rising starlet Shaun Murphy in his first match at The Crucible.

And unless he is on top of his game, then the 19-year-old from Irthlingborough could cause a massive upset.

World number 30 Gray is now guaranteed £21,000 the biggest cheque of his six-year professional career - and a match against holder Peter Ebdon or holder Quinten Hann.

In a game dominated by mistakes and low scoring, Hendry managed a top break of only 40.

Gray knocked in breaks of 53 and 55, but agreed: ‘‘I’ve never seen Stephen miss so many easy balls.

‘‘I wasn’t worried at being 2-0 down, but I was worried how badly I was struggling. I beat Ronnie O’Sullivan at the world championship a couple of years ago.

‘‘But a semi-final of a ranking event is a lot more important so this has got to be my best win,’’ added the Morden-based professional who also knocked out former world champion John Higgins in the last 32.

‘‘I’m surprised I hadn’t made a quarter-final until this week, so it’s nice to redeem myself and get into the semi-finals straight away.’’

Nigel Bond, runner-up to Hendry in the 1995 world final, is surprised as well.

He finds himself in the last four having lost seven out of his eight opening-round matches this season.

‘‘This has softened the blow at not qualifying for Sheffield,’’ said the former British Open champion following his 5-1 success over world number 15 Dave Harold.

‘‘But after this week I don’t really want the season to end. I’m not sure where this form has come from.

‘‘I’ve been playing well in practice and it’s just a case of bringing your practice form into matches.’’

Bond from Darley Dale made the perfect start with a break of 131. Unfortunately neither player could attain that kind of standard for the rest of the match.

Harold was 3-0 down before he opened his account, but it was his only success as Bond set-up a meeting tomorrow against Jimmy White or Stephen Lee.