Justine Henin overcame her toughest test yet to reach the semi-finals of the French Open as she bids to win the event for the third successive year.
The defending champion beat Serena Williams 6-4 6-3 to move into the last four, where she is joined by second seed Maria Sharapova.
Sharapova saw off the challenge of fellow Russian Anna Chakvetadze 6-3 6-4 to set up a semi-final clash with Ana Ivanovic, while Henin will face the other Serb left in the draw, Jelena Jankovic.
There was precious little to choose between Henin and Australian Open champion Williams in the first set, but it was the Belgian who claimed the decisive break.
Henin then grew stronger in the second set, breaking at 2-2 and then again to book her passage to the semi-finals.
The first set had been just the sort of tight encounter that had been expected, Henin winning just one point more than her opponent and with both players hitting the same number of winners and unforced errors.
The second set, however, was a different story. After trading breaks at the beginning of the set, Henin secured a further break to edge 3-2 ahead and consolidated with an efficient service game for a 4-2 lead.
Williams held in her next service game to keep the pressure on the top seed but was unable to follow it up with a break of serve.
Henin raced to 40-15 against the Williams serve in the ninth game and closed out the match at the first opportunity.
Playing in her fifth French Open, Sharapova reached the last four for the first time with a comfortable win over ninth seed Chakvetadze.
Sharapova had to save three match points to get past Switzerland's Patty Schnyder, but she earned decisive breaks at key times to subdue Chakvetadze.