Henman had played well all week at Queen's Club

Henman, seldom at his best, won 6-3 7-6 and will now play Lleyton Hewitt after Rafael Nadal retired with injury.

Tursunov, the 15th seed, beat Henman at this year's French Open and Australian Open as well as Wimbledon in 2005.

Henman said: "He is so powerful - he can hit incredible shots, so it's good to get through and continue my form."

Highlights: Henman and Hewitt progress

Interview: Tim Henman

Interview: Lleyton Hewitt

Henman took the first set with relative ease, but needed a tie-break to seal a messy second set when both men made a hatful of unforced errors.

Clearly relieved at the end, Henman said: "Tursunov has beaten me on a couple of big occasions.

"He's an awkward guy to play against and you never really feel that the match is under your control.

"I feel good about my game - I've played well here in the past. After struggling in the last few years on grass, I feel much more comfortable this year - and it shows in the way I've been playing."

Injured shoulder

Nadal and Hewitt were locked at one set all when Nadal signalled to umpire Gerry Armstrong that he could not carry on.

The Spaniard had needed treatment on his left shoulder throughout the match and after losing the second set shook his head and walked off court.

Hewitt admitted he was looking forward to taking on Henman.

He said: "It's always good fun playing Tim - it will be great to test each other out before Wimbledon.

"He's looking pretty confident on grass this year, so it's going to be a tough match."

Henman said: "Lleyton is a great grass-court player and has beaten me enough times. But at least I beat him the last time."

Defending champion Andy Roddick was a confident 6-4 6-3 winner over Chilean Fernando Gonzalez, setting up an all-American semi-final against James Blake.

Blake advanced after a back injury forced France's Gael Monfils to retire in thier encounter.