There were mixed fortunes for the Williams sisters at Wimbledon on Wednesday as Serena bowed out but Venus marched on.

Younger sibling Serena coped well with the calf injury she sustained on Monday but in the end had to bow to top seed Justine Henin, who won an exciting quarter-final 6-4 3-6 6-3.

However, the family's chance of adding a sixth Wimbledon singles title is still very much alive after Venus thrashed Maria Sharapova 6-1 6-3 with an impressive performance in the last 16.

Henin edged a tight tussle against Serena who seemed more troubled by strapping on her hand and wrist than she did by the calf problem which had almost forced her to quit her previous match against Daniela Hantuchova.

Her backhand appeared to be affected and that side produced the most errors - a fact Henin soon picked up on.

The top seed took the first set with the only break in the ninth game but Williams hit back in the second to set up a deciding set.

In it, Henin raced 5-1 ahead but failed to serve out as Williams showed all of her renowned fighting qualities.

However, she finallly completed victory on her second match point when Williams sent one of those backhands long.

"I'm very happy to come through," said Henin. "Physically it's been pretty hard. I was a little bit disappointed to lose a single set this week."

"It's the kind of victory that gives the confidence that I really needed here."

Williams, who suffered a calf problem in the previous round, insisted the injury was "a lot better" but still rated her fitness at just "40 or 50%".

Earlier Venus kept her hopes of a fourth Wimbledon title alive in stunning fashion.

The American star produced a fine serving display and did not have to face a break point as she cantered to victory.

In contrast, an out-of-sorts Sharapova struggled in the blustery conditions on Centre Court, her high ball toss being severely affected.

She faced 19 break points in all and only during a 22-minute game in the second set did she look as if she could really compete with the former champion.

Williams swept through the first set in just 32 minutes but had her progress halted by rain at 1-1 in the second.

That third game went on and on when play resumed - Sharapova saving seven break points before holding - but even that could not change the course of the match.

Williams progresses to meet Svetlana Kuznetsova in the last eight on Thursday.

"In my whole life I've been a big-match player," Williams said. "I always feel very confident.

"The only thing that can happen is if I make some errors, then my opponent can get in the match. Today those errors weren't there."

Sharapova admitted afterwards: "You really can't be surprised because I know what she's capable of. I know she can produce great tennis.

"But she hasn't been playing the best tennis here, I saw some of the matches she's played. She was not nearly as good as she was today."

In the day's other ladies' singles match, French 18th seed Marion Bartoli came from a set down against Michaella Krajicek to set up a semi-final meeting with Henin.

The surprise package of the ladies' draw followed up her victory over third seed Jelena Jankovic with a 3-6 6-3 6-2 win on Court Two.

Service breaks had been the dominant feature of Bartoli's win over Jankovic on Tuesday, but that was not the case 24 hours on.

Krajicek secured the only break of the first set in the sixth game which was enough for her to move ahead.

However, that was to be her only joy on the Bartoli serve which was much improved from her previous match.

The French star took the second set, again with the only break, to wrest the initiative away from her Dutch foe and then dominated the decider to reach her first Grand Slam semi-final.

Bartoli said she caught up on some sleep in the rain delay, which helped her to win the match: "The match against Jelena was tough. I got to bed at 11.30 and was awake this morning at 7.30, so I was really short of sleep. I need at least 10 hours.

"So I slept for an hour during the rain delay. I think after that I was feeling much better.

"It was good for me to have the rain delay."