NEW YORK -- Unseeded Elena Bovina, a Russian teenager, became the first player to reach the third round at the U.S. Open on Wednesday, upsetting fifth-seeded Jelena Dokic 6-3, 6-2.

Serena Williams, who won the Open in 1999, cruised past Dinara Safina 6-0, 6-1. Williams, winner of the last two Grand Slams at the French Open and Wimbledon, moved comfortably into the third round, whistling 16 winners to just two for Safina.

Lindsay Davenport, the 1998 Open champion, was leading her night match against Petra Mandula 6-4, 2-2, when play was halted because of rain. While organizers called off all the in-progress matches on other courts, they held out hope of being able to resume Davenport's second-rounder.

Dokic struggled with injuries through the early part of the season but prepared for the Open by playing five straight weeks.

She never seemed comfortable against Bovina, who pushed her to three sets in their only previous meeting at Indian Wells.

"I didn't play well, I didn't move well,'' Dokic said. "I made too many errors. I didn't play the points smart. She was dictating.''

Dokic was forced to withdraw from warmups at Montreal and New Haven because of a hamstring injury and was booed after losing to Chanda Rubin at Los Angeles.

Bovina made fast work of her, ripping four aces and taking advantage of Dokic's 29 unforced errors in a match that lasted just one hour.