Venus on course for Olympic double

The Williams sisters are dominating the doubles

Venus Williams is on course to complete a stunning run of tournament wins this year after qualifying for the final of the women's doubles at the Olympics - and US tennis coach Billie Jean King believes she is still a long way short of her best.

Williams and her younger sister Serena brushed aside fifth-seeded Belgians Els Callens and Dominique van Roost 6-4 6-1.

They will face Kristie Boogert and Miriam Oremans in Thursday's final after the Dutch pair beat Natasha Zvereva and Olga Barabanschikova of Belarus 6-3 6-2.

Venus, the Wimbledon and US Open champion, had already qualified for Wednesday's women's singles final, in which she will face Russia's Elena Dementieva.

The elder Williams sister is on a run that started with her victory at Wimbledon, her first Grand Slam title, and was followed by a triumph at Flushing Meadows, where this year she succeeded Serena as champion.

Williams could improve many aspects of her game

Venus has now won 31 matches in a row, despite still making too many double faults on her serve, and - by her own admission - having many other areas of her game that she could improve.

US coach and tennis legend King, winner of 12 Grand Slam singles tournaments, said: "I think Venus is at 75% of her potential in singles, and 50% in doubles."

That should be more than enough for Williams to win two gold medals at the Olympics.

As second seed, Williams is highly fancied to beat 10th-seeded Dementieva.

The Russian, 18, won her only previous meeting with Williams last year in the Fed Cup, but the match was essentially meaningless because the US team had already clinched a victory.

Playing well

Dementieva does not sound confident. "That was last year. This is different," she said. "She's playing very well now. I don't know if I can beat her, but I'm happy to be in the final."

Dementieva emerged as a potential star at this year's US Open, where she reached the semi-finals before losing to Lindsay Davenport.

"She's playing well," Williams said. "She's got a good game. I'm sure she'll want to take first place, and I will too."

Venus is at 75% of her potential in singles, and 50% in doubles

  Billie Jean King

King said: "Venus to me is like on automatic pilot. She is just playing so well. [But] her serve can be a lot better," King said. "She knows it. She's working on it. We work on everything.

"I find with Venus, you've got to keep it fun. That's the operative word with her - fun.

"And give her new challenges. Champions love challenges. Like, 'I bet you can't do this.' And she'll go, 'Yeah I can. I'll show you.'"