World number one Amr Shabana of Egypt was pushed to the very limit of his physical endurance yesterday by England?s James Willstrop, narrowly booking his place in the Bermuda Masters semi-finals after four punishing games.

The tournament favourite, who moved to the top of the world rankings at the beginning of this month, will play world number five Thierry Lincou, after the Frenchman defeated England?s Nick Matthew 5-11, 11-5, 12-10, 11-7 in the second quarter-final of the day at BHS.

In arguably the match of the tournament so far, both Shabana and Willstrop were barely able to stand in the immediate aftermath of their marathon clash, with the Egyptian eventually collapsing to the floor in total exhaustion while his opponent bent double in the back corner sucking desperately at the air.

Though Willstrop only just failed to take the match into a fifth and final game, his determination throughout could not be faulted. In the end though, the wiry Egyptian moved that little bit more sharply in the match?s latter stages, while the indiscipline which characterised his early career was nowhere to be seen.

The squash was tight and competitive in the first, though Willstrop appeared to be nursing a slight strain in his lower back and was not twisting and turning with his usual freedom.

Nevertheless, a couple of borderline refereeing decisions worked in his favour with the score at 9-9, handing him the early advantage.

Shabana predictably came out firing in the second, winning it comfortably 11-5 ? a swift prelude to an absolutely mammoth, energy-sapping third which lasted for well over half an hour.

At 6-9 down in that game, Willstrop seemed a spent force. But displaying that good old Yorkshire grit which so often comes to the fore when he finds himself up against it, the boy genius from Pontefract ultimately fought his way back to 10-10 and looked to have the momentum running with him.

But Shabana dug in again during a sensational tiebreak, in which one incredible rally after another had many in the crowd shrieking with astonishment, and via a pair of strokes, the last of which was marginal, took the game 14-12.

Willstrop battled on bravely in the fourth, however, despite clearly tiring legs and a barrage of winners from a pumped up Shabana.

At 10-7 to the world number one, the pair were involved in two of the longest rallies of the tournament - the first one ending anti-climatically in a let and the second going Shabana?s way to give him a victory which required every last drop of strength at his disposal.

The final score read 8-11, 11-5, 14-12, 11-8.

?It doesn?t come any harder than that,? Shabana said afterwards. ?There is a lot more pressure on me now that I?m number one in the world because you are the target for everybody to beat.

?When you come up through the ranks, you can win a match or lose a match and it is not the end of the world, but when you are at the top there is an added responsibility. I had to put in a crazy amount of effort today to beat James and I?m just happy it?s all over.?

A phlegmatic Willstrop, meanwhile, said the defeat would only spur him on to train harder.

?Squash is an absolutely brutal game and that was a brutal match,? said the world number three.

?Shabana was terrific but I managed to hang on in there. There are so many good players around these days that an easy match is a rarity at the top level and for me it is just a matter of putting even more work in if I want to come out on top.?