MELBOURNE, Australia (AP) -- Defending champion Serena Williams won her 16th consecutive match at the Australian Open on Wednesday, taking less than an hour to beat Camille Pin 6-3, 6-1 and advance to the third round.

Two days after scraping past China's Li Na in the first round, Williams lost her opening service game to Pin, who is ranked 130th.

But the seven-time Grand Slam singles champ recovered and overpowered Pin, winning six straight games to take the first set in 25 minutes.

Williams dropped her serve again in the second set, but broke Pin four times and finished with 30 winners against only six for the French player.

"It's never as easy as it looks," Williams said. "I'm just happy to be getting through the rounds."

The narrow win over 52nd-ranked Li and the surprising first-round loss by older sister Venus was motivation for Williams on Vodafone Arena.

"I definitely had some things I wanted to work on today, so it was cool," she said.

Williams won the Australian Open in 2003 and 2005, missing the 2004 event because of injuries.

"The last two times I played here, I did really well," she said. "I'm just hoping to keep it up."

Top-ranked Lindsay Davenport got a tough workout from Karolina Sprem before advancing with a 7-6 (4), 6-3 victory.

French Open champion and eighth-seed Justine Henin-Hardenne moved on with a 7-6 (2), 6-1 win over Hana Sromova, who badly turned her right ankle after the second game of the second set and lost the next five games.

Davenport traded breaks with Sprem in the third and fourth games, then forced a tiebreaker by winning the 12th game at love.

Trailing 3-1, Davenport rallied after Sprem double-faulted, winning six of the last seven points and claiming the first set with consecutive forehand winners.

"After being down in the tiebreaker, to come back and construct a few really good points, it was very key to get out of that," Davenport said.

The 2000 Australian champion, had six breakpoint chances in the second set before finally converting after the sixth game went to deuce six times.

Two of Davenport's three previous wins over Sprem have come at majors.

She won in the fourth-round here last year en route to the final and the quarterfinals at Wimbledon in 2004, after Sprem had upset then defending champion Venus Williams.

Sprem worked Davenport around with some big serves and powerful forehands, but let herself down with nine double-faults.

Davenport was consistent, winning 80 percent of points on her first serve, firing six aces, hitting 18 winners and playing what she described as "nice contained tennis."

"It was a really tough match," she said. "I knew she definitely had the ability to be dangerous, and that was the best that she's played against me.

"I felt like I was hitting the ball well, just not quite hitting my spots."

Davenport said Sprem's power surprised her at times.

"Maybe I was just caught a little off guard," she said. "But the more aggressive I could be, I felt like the match was in my favor.

"I was able to come through not playing perfect tennis but I still thought I did some things well -- everything about the match was a positive for me."

Davenport next plays 25th-seeded Maria Kirilenko, who had a 7-6 (1), 6-4 win over fellow Russian Galina Voskoboeva.

No. 4 Maria Sharapova faced American Ashley Harkleroad in a later match.

On the men's side, No. 7 Ivan Ljubicic, No. 8 Guillermo Coria, No. 11 David Ferrer and No. 18 Mario Ancic advanced.

No. 13 Robby Ginepri failed to reproduce his successful marathon efforts of the U.S. Open, falling in five sets to German qualifier Denis Gremelmayr after leading by two sets and 3-0.

Gremelmayr won six of the last seven games in the third set en route to a comeback 2-6, 5-7, 6-4, 6-3, 6-3 victory. Ginepri set a record for most five-set matches played in a single Grand Slam tournament, playing four five-setters before losing a U.S. Open semifinal to Andre Agassi.

No. 2 Andy Roddick was scheduled to play Wesley Moodie.

On Tuesday, Martina Hingis returned to Rod Laver Arena a little older, a little stronger and a little wiser, easily winning her first match in Melbourne since 2002 over Vera Zvonareva 6-1, 6-2.

Men's winners Tuesday included top-ranked Roger Federer and No. 3 Lleyton Hewitt, the home favorite who had to rally to beat the Czech Republic's Robin Vik in five sets.