Henin, apart from a brief second set blip, was in total command as she brushed aside Sybille Bammer of Austria 6-2, 6-4 for her 18th straight win at Roland Garros.

Williams, seeking a second Paris title five years after her first, underlined her threat by blasting past Russia's Dinara Safina 6-2, 6-3.

The two last played here in the 2003 semi-finals when Henin won a superb three-setter that saw Williams leave the court in tears as the Paris crowd backed the underdog Belgian.

"Justine is really good here. Usually I don't have to peak too soon but this will be different," Williams said. "But I am playing the clay court game really good.

"I don't want to reflect on what happened in 2003 any more. This is a new year and we are both different people. I have matured and if the crowd gets involved I can just zone out."

All 16 remaining women were scheduled to play during the day with the quarter-final line-up set to be decided. First through minutes before Williams sealed victory was 18-year-old Czech prodigy Nicole Vaidisova who reached the last eight for a second straight year with a comprehensive 6-3, 6-1 win over Italy's Tathiana Garbin.

Last year's losing finalist Svetlana Kuznetsova followed with an impressive 6-4, 6-3 win over Israeli Shahar Peer, a player she had lost to twice already this year, notably at the same stage in the Australian Open.

Australian Open champion Williams blasted out of the blocks against Safina, the 10th seed and sister of Marat, the former men's world number one.

She broke her opponent's first two service games to go 4-0 up and wrapped up the set 6-2 in 36 minutes.

The second set was a different story with both players struggling to hold on to their serves and Safina, a quarter-finalist here last year, at times matching Williams for power off her groundstrokes.

The pair exchanged two service breaks each to get to 3-3 but in the following game Williams made the difference with a third service break before moving 5-3 ahead.

There was no way back for Safina who had her service broken for the sixth time in the match as Williams returned to the French Open quarter-finals for the first time since 2004, the last time she played at Roland Garros.

Henin was just as dismissive racing out into a commanding set and 4-0 lead out on the Suzanne Lenglen Court.

Bammer, the only mother in the main draw, clawed her way back with two breaks of serve to pull level at 4-4, but Henin promptly snuffed out any hints of a comeback by winning the next two games.

Vaidisova, employing a new service action to avoid the shoulder pain that sidelined her earlier this year, said that she had learned from her semi-final appearance last year.

"I've been working on it to cut out the mistakes and it's been working," she said. "I've been under no pressure here as I have been out for a month. It's just great not to have any pain."

Vaidisova will take on the winner of the tie between Jelena Jankovic of Serbia and the remaining French hope Marion Bartoli.

Kuznetsova saw off the challenge of 20-year-old Peer by winning five games in a row from 5-4 up in the firt set.

Peer did break back to get to 5-3, but that was as close as she got.

The third seeded Kuznetsova will play the winner of the tie between Ana Ivanovic of Serbia and Anabel Medina Garrigues of Spain for a place in the semi-finals.