By Caroline Cheese
BBC Sport at Wimbledon
Justine Henin came through a bruising encounter with Serena Williams to reach the semi-finals at Wimbledon.
Henin remains on track for her first Wimbledon title
The world number one won the only break point of a high-quality first set before serving out in clinical fashion.
But Williams, whose movement appeared to be hampered by her calf injury, fought back magnificently.
The former champion grabbed the second set and then came back from 5-1 down in the decider but Henin held her nerve to triumph 6-4 3-6 6-3.
"I was a bit nervous at the end," said Henin.
"Mentally it was very difficult so I'm very happy to come through. It's the kind of win that gives me a lot of confidence for this tournament."
If I had been healthy I think I would have won, definitely
Williams revealed later she had been suffering from a sprained thumb, which affected her backhand.
"My leg is doing a lot better but when I slipped in the third set (against Hantuchova), I hurt my thumb," said the Australian Open champion.
"I'm definitely not 100%. I was probably at 40 or 50% maximum.
"She played a very high-quality game, probably some of her best tennis. If I had been healthy I think I would have won, definitely.
"It was a last-minute decision to play and I was almost able to do it. Considering the circumstances, I think I did pretty well."
Henin, who now faces surprise semi-finalist Marion Bartoli, will be favourite to take her first Wimbledon title after seeing off Williams - the 2002 and 2003 champion.
Richard Williams had advised his daughter not to play her quarter-final match after suffering a calf strain in a dramatic fourth-round win over Daniela Hantuchova.
But despite moving gingerly at times, Williams' injury did not prevent her from engaging in some fearsome baseline exchanges with Henin.
Serve dominated the first set, but Henin, moving Williams around with her greater variety of shot, grabbed the crucial break at 4-4 and she served out with ease.
After an exchange of breaks in the second set, Williams forced Henin into two forehand errors as she established a 5-3 lead.
Serving to level the match, Williams demonstrated her absolute determination to win by making a Hawkeye challenge.
Williams, like her sister Venus, has been reticent about using the new technology but when an ace was called out on set point, she immediately challenged - and was proved correct.
But Henin stepped up the pressure in the third set, returning brilliantly to establish a double-break lead at 5-1.
However, the drama continued as a nervy Henin threw in two double-faults to allow Williams back into the match.
The American closed the gap to 5-3 but Henin finally emerged victorious when a tired Williams sent a backhand long.
Bartoli earlier reached her first Grand Slam semi-final with victory over Michaella Krajicek.
The 22-year-old edged the match - a first Slam quarter-final for both players - 3-6 6-3 6-2 on Court Two.
Bartoli dropped the first set but then took control, breaking twice as she closed out the final set comfortably.