Serena Williams and her quest for a third BNP Paribas Open is on track after she upstaged defending champion Simona Halep in straight sets of their quarter-final.

Williams was far too strong and powerful for the fifth-seeded Romanian as triumphed 6-4 6-3 at Indian Wells on Wednesday.

Awaiting world number one Williams in the semis is third seed Agnieszka Radwanska, who edged Petra Kvitova 6-2 7-6 (7-3).


SERENA FLEXES HER MUSCLES

Williams found herself a break up early in the first set but could not close it out after going 5-3 up, as Halep showed some fight to get back on serve.

Halep trailed love-40 very quickly, and while she recovered to 30-40, Williams would not be denied.

Williams was efficient in the first set, taking her one break-point opportunity and playing clean service games to quickly tie up the match and send Halep packing after a little over an hour on court.


KVITOVA FALLS SHORT

Kvitova - the eighth seed - had her chances against Radwanska but was unable to prevent a straight-set loss.

In a rematch of the WTA Finals showpiece in Singapore last year, Pole Radwanska stormed out of the blocks as she opened a 5-1 lead before closing it out.

Kvitova stepped it up in the second, breaking twice to earn a 4-2 advantage before the Czech was outlasted by Radwanska, who raced out to a 4-0 lead in the tie-break.


ERRORS PROVE COSTLY

Kvitova tallied 22 unforced errors and seven double faults, which proved costly against Radwanska, who will jump up to second in the WTA rankings on Monday.

Williams hit 28 winners and 24 unforced errors en route to the semis.

Halep won just 58 per cent of her first service points.


RADWANSKA BRACED FOR SERENA

"I just hope I can really play good tennis that I was playing last few days, and that's it. [The] goal is to win, but it's not gonna be easy, that's for sure," Radwanska said.

"[Radwanska] knows how to play in big stadiums and big matches, big games," said Williams post-match. "Obviously she does everything so well, including running, and this is a good surface for her because it's a slow surface. I think I expect there will be a lot of long rallies."

Kvitova opted to focus on the positives afterwards, saying: "I think that the tournament gave me good signs. I have been working hard before the tournament, and that I think was really paid off during this week."


AZARENKA, PLISKOVA EYE FINAL FOUR

Seeds Victoria Azarenka and Karolina Pliskova can join Williams and Radwanska in the semis on Thursday. Azarenka takes on Magdalena Rybarikova, while Pliskova meets Daria Kasatkina earlier in the day.