MELBOURNE, Australia — Serena Williams has advanced to a fifth Australian Open final and ended any chance of an all-Chinese championship match in the season's first major.

Defending champion Williams wasted four match points before finishing off a 7-6 (4), 7-6 (1) semifinal win with an ace against Li Na on Thursday, a day after her sister Venus lost to the Chinese player in the quarterfinals.

Serena Williams has a 100 percent conversion rate so far in finals at Melbourne Park, winning the title every time she's played for the championship since beating Venus here in 2003. The winning sequence has been every odd-numbered year so far.

"I had so many match points and I blew it and I knew I couldn't mess up my serve because she never gives up," Williams said. "She's a real, real amazing fighter."

China had two players into the semifinals of the same major for the first time.

Zheng Jie had another chance to become the first Chinese player to reach a Grand Slam singles final when she took on seven-time Grand Slam winner Justine Henin in the later semifinal.

Zheng reached the 2008 Wimbledon semifinals, just months after Henin retired from tennis while holding the No. 1 ranking.

Henin is unranked and two tournaments into a comeback from 20 months off the tour, hoping to emulate fellow Belgian Kim Clijsters' win at the U.S. Open. Clijsters was only three tournaments into a comeback from two years off, and playing on a wild card entry, when she won the U.S. Open last September.

In the first semifinal, Williams broke Li's service in the opening game and maintained the break until the 10th game.

Li fended off a set point in the ninth game before holding, then broke Williams' serve in the 10th game to even the match at 5-5.

In the tiebreaker, Williams picked up four of her last five points on unforced errors by Li and then clinched the 58-minute set with a second-service ace.

The second set went with serve, with Li fending off three match points in the 10th game and another in the 12th to force a second tiebreaker. Again, Williams dominated the tiebreaker to race to a 6-1 lead, closing with her 12th ace of the match.

Venus Williams, who had a chance to serve for the quarterfinal on Wednesday against Li before she lost, was watching from the stands. She was to partner Serena later in a women's doubles semifinal against sixth-seeded pair Lisa Raymond and Rennae Stubbs.

No. 5 Andy Murray and No. 14 Marin Cilic will meet in a semifinal Thursday night after ousting the second- and fourth-seeded players in the quarterfinals.

With Jo-Wilfried Tsonga taking out No. 3 Novak Djokovic late Wednesday night, there was nobody left in the draw who has beaten Roger Federer in a major.

Murray was leading defending champion Rafael Nadal by two sets and a break when the Spaniard retired due to a knee injury; Cilic beat U.S. Open champion Juan Martin del Potro in five sets.

Tsonga beat 2008 champion Djokovic 7-6 (8), 6-7 (5), 1-6, 6-3, 6-1, in a reverse of the outcome of their final here two years ago, and will meet top-ranked Federer in a semifinal on Friday.

Federer advanced to his 23rd consecutive Grand Slam semifinal on Wednesday with a 2-6, 6-3, 6-0, 7-5 win over No. 6 Nikolay Davydenko.

Davydenko's 13-match winning streak was the hottest on tour and included wins over Federer at the season-ending championship in November and at Doha earlier this month.

The Russian unloaded everything he had on Federer for a set and a half, until Federer's big-match experience kicked in, he switched gears and won 13 straight games to take the match away from Davydenko.

Federer has made the semifinals or better at every major since Wimbledon in 2004, a record he considers "definitely one of the most incredible things I have in my resume."

Before Federer, Ivan Lendl and Rod Laver shared the record at 10.