The two-time champion rallied from 4-1 down in the first set and beat Australia's Alicia Molik 7-6 (4), 6-3 today to reach the third round of Wimbledon on another day of rain delays at the All England Club.

"I just got really angry," Williams said. "I thought it was unfair that I got down so far. I was like, OK, it's just one break. But 4-1 looks worse than one break."

Also getting past the second round was third-seeded Andy Roddick, who defeated 114th-ranked Danai Udomchoke of Thailand 6-3, 6-4, 7-6 (3).

Roddick, serving at speeds up to 140 mph aces and 40 winners and broke three times. Udomchoke converted only one of nine break points.

"I felt like I played some of my best tennis in the third-set tiebreak," Roddick said. "I was a bit up and down mentally in the match, but got through."

Top-seeded Justine Henin took one hour to oust Vera Dushevina of Russia 6-0, 6-4 on Centre Court to make the third round in her bid for the only Grand Slam title to elude her.

"I hope I can make it here one day," said Henin, a two-time losing finalist at Wimbledon. "I hope I will have another chance and be at my best level. It's a good motivation for me."

Henin played with a long strip of black tape on her right shin. She said she has been bothered by tendinitis in her right foot, but that it hasn't affected her game.

Play was interrupted by rain for 45 minutes early in the day, and suspended again in late afternoon by heavier showers. The delay came with four-time defending champion Roger Federer — seeking his 50th straight win on grass — leading 6-2, 7-5, 2-0 against 18-year-old Juan Martin del Potro of Argentina.

Williams, who also struggled in the first set of her opening-round win Monday over Lourdes Dominguez Lino, fell behind again early against Molik in windy conditions on Court 1. But she finally got her power game going and finished with 10 aces and 35 winners to 18 errors.

"I'm playing OK," said Williams, who rated her performance six out of 10, compared to two out of 10 for the first round. "I actually don't think I'm playing that great, no."

Williams, who was affected by a tight hamstring in her first match, said she experienced no problems Wednesday.

"Not at all," she said. "Not today. I was feeling better. Don't jinx me."

Williams showed lots of emotion during the match as her sister, Venus, and parents watched from the stands.

"The angry Serena is very crazy to say the least," she said. "Sometimes she comes out."

The turning point came in the tiebreaker with Molik leading 4-2. The Australian made groundstroke errors on the next four points and Williams pounded a 121 mph ace down the middle to close out the set — punctuated by a fist pump and scream of "Come on!"

The match ended in bizarre circumstances on Williams' third match point in the final game. A line judge called Molik's shot wide, but the two continued playing until Williams hit a winning forehand volley.

The players approached the net to congratulate each other, but Molik was allowed to challenge the line judge's call. The new "Hawk-Eye" replay system showed the ball was out. The two smiled, and Williams saluted the crowd.

Williams said she didn't mind that Molik contested the call.

"I told her, `You may as well. I would have challenged it, too. I'm not upset. I'm not going to hold it against you,"' Williams said. "She was like, `OK."'

A similar incident occurred at the end of Henin's victory. Serving for the match, Henin saved a break point, then produced two straight aces to finish the contest. Dushevina challenged the call on the final ace, but the replay showed the ball was on the line.

In other women's play, French Open runner-up and No. 6-seeded Ana Ivanovic beat Melinda Czink of Hungary 6-0, 7-6 (3) in a first-round match.

Also reaching the second round were No. 12 Elena Dementieva, No. 14 Nicole Vaidisova and No. 17 Tatiana Golovin. Ninth-seeded Martina Hingis, the 1997 champion, defeated Aiko Nakamura of Japan 6-1, 6-2 to reach the third round.