The fifth-seeded Williams continued her success against Hingis today, upsetting the top seed, 4-6, 6-2, 6-3, in the semifinals of the $535,000 estyle.com Classic.

It was the first meeting between the players since Williams defeated Hingis in last year's U.S. Open final to claim her first Grand Slam singles title.

Williams has compiled a 24-6 record this season, including 19-4 on hard courts. The 18-year-old claimed her only tournament win in 2000 in February on hard courts at the Faber Grand Prix in Hannover, Germany.

Hingis has won four titles this season, including the Ericsson Open on hard courts, and has reached the finals at three other hardcourt events, including the Australian Open.

The Swiss teenager has won a WTA Tour-leading 48 matches this season, against only eight losses. One of those defeats came against Serena's older sister Venus in the quarterfinals at Wimbledon, where Venus started her run of three straight tournament wins.

Williams has four of seven career meetings and three straight against Hingis, including a 6-3, 7-5 semifinal victory in last year's event en route to the title. Williams defeated Hingis by the identical score in last year's U.S. Open final.

Second seed and California native Lindsay Davenport looks to move one win away from her first title since April when she battles Russian teenager Elena Dementieva in tonight's second semifinal.

Davenport, a two-time champion here, moved into the semifinals on Friday night as she breezed past eighth seed Sandrine Testud of France, 6-4, 6-2.

Ranked No. 2 in the world behind Hingis, the 24-year-old Davenport is seeking her third title of the season and first since early April. Both of her tournament wins have come on hard courts, including the Australian Open in January.

The 18-year-old Dementieva advanced to her second hardcourt semifinal of the season on Friday as she rallied past American Lisa Raymond, 2-6, 6-1, 6-4.

Dementieva, ranked No. 32, also reached the semifinals at Indian Wells, California in March, which Davenport won easily, 6-2, 6-1. Davenport is 3-0 overall against the Russian.

First prize is $87,000.