Jelena Jankovic's credentials as a dark horse for the French Open title were further enhanced as she prevailed in a high-quality third-round clash with Venus Williams yesterday.

The in-form Jankovic, seeded four, outlasted the American and claimed a 6-4 4-6 6-1 win on Philippe Chatrier court.

The Serbian plays either Elena Dementieva or Marion Bartoli in the next round.

Jankovic broke Williams, the 26th seed, in the first game of the match and managed to hold her serve for the remainder of the first set to take it in 30 minutes.

The Serbian's dead-eye serve was particularly hurting the American.

Williams hit back at the start of the second set, going 3-0 ahead, but Jankovic pulled it back to 3-2 by forcing a break in the fifth game.

An improving Williams immediately broke back and served for the set at 5-3 up but Jankovic produced a superb game, breaking to 15 despite being forced on the defensive by Williams' power.

The Serb ruined her good work by dropping her serve next though, allowing Williams - whose forehand was by that time booming - to tie the match.

Jankovic held the whip hand early in the third set after breaking in the third game, Williams smashing a backhand long after saving the first of two break points.

A wilting Williams was then broken in her next game, following up a double-fault with a wayward forehand, to put Jankovic in sight of victory at 4-1 up.

The fourth seed sealed the game on her first match point, as she broke Williams for the third time in the deciding set.