DOHA: Venus Williams wilted in Qatar's desert heat on Tuesday as feisty Russian Elena Dementieva staged a remarkable WTA Championship comeback to defeat the title-holder 3-6, 7-6, 6-2.

Williams had led 6-3, 3-1 before Dementieva recovered to record only her third win in 12 meetings with the great American, and first since 2004. Dementieva, playing in her ninth season-ender, stunned the seven-time major winner, clinging on even as Williams served for the match at 6-5 in the second set. The 28-year-old Russian levelled the match when Williams double-faulted on a fourth set point in the tie-breaker, before sprinting into a commanding 4-0 lead in the decider. She secured the win with a running, crosscourt backhand after a 2hr 41min marathon.

Dementieva's shock win now adds extra spice to Williams' second group game against sister Serena where she will have to win to stay alive in this eight-woman, $4.55 million event. Serena, meanwhile, saw off French Open winner Svetlana Kuznetsova 7-6, 7-5 as she began her campaign to reclaim the world No 1 spot from Dinara Safina. The eight players are split into two round-robin groups here with the top two in each making Saturday's semi-finals with a $1.5 million cheque awaiting Sunday's winner.

Earlier, Belarussian sixth seed Victoria Azarenka marked her tournament debut with a 6-2, 6-3 win over Jankovic. Jankovic only squeezed into this tournament as the eighth and last qualifier, boosted by a run to the Tokyo final. Azarenka, 20, had lost three of her four career meetings with Jankovic.

Lyon Grand Prix

LYON: Top-seeded Jo-Wilfried Tsonga served 14 aces and needed two tiebreakers to beat Kevin Kim of the United States 7-6 (5), 7-6 (5) in the first round of the Lyon Grand Prix on Tuesday.

Neither player faced a break point in the first set, but Kim saved two in the second as Tsonga started to get on top. Kim missed his chance to level the match as Tsonga rallied from 5-3 down in the second set tiebreaker.

Third-seeded Ivan Ljubicic of Croatia also progressed after beating Martin Vassallo Arguello of Argentina 6-3, 6-4. Ljubicic, looking for his first title this season, won 29 of 33 points on first serve including seven aces. The defeat would have been heavier for Vassallo Arguello if he hadn't saved 10 of 12 break points.

Seventh-seeded Benjamin Becker of Germany beat Paolo Lorenzi of Italy 6-2, 6-2, while No 8 Albert Montanes of Spain topped Fabrice Santoro 6-4, 6-4.