Serena to face Azarenka in US Open final

Defending champion Serena Williams beat China's Li Na 6-0, 6-3 on Friday to reach her second consecutive US Open final.

With the victory, the top-seeded Williams set up a rematch of last year's final against Belarussian second-seed Victoria Azarenka, who beat Flavia Pennetta in Friday's other semi-final.

Williams, a 16-time Grand slam winner seeking her fifth US Open title, enters Sunday's final having not dropped a set at Flushing Meadows this year.

Belarussian Victoria Azarenka reached her second straight US Open final with a 6-4, 6-2 win over Italy's Flavia Pennetta earlier.

"I'm so excited. It's been a long road to the final. It's an amazing feeling, to fight for the trophy," said Azarenka, a former US Open junior champion and mixed doubles winner. 

Both players struggled to keep their serve on centre court with 13 breaks of serve in the 18 games but Azarenka's power was too much for the enterprising Pennetta, who returned from a serious wrist injury to reach her first Grand Slam semi-final. 

There were five service breaks in a row before Azarenka, the Australian Open winner, held to win the set after an intense battle where the unseeded, 31-year-old Pennetta saved five set points. 

The second set followed a similar pattern, with three broken serves before Azarenka turned up the power, holding to go up 3-1 in the set and then breaking Pennetta, ranked 83rd in the world, with a powerful backhand winner. 

Azarenka, 24, also struggled to make her serve count though, offering a glimmer of hope to the 31-year-old Italian when she went wide with a return on break point. 

But once again Pennetta was unable to hold, twice finding the net to hand Azarenka the chance to serve for the game and despite a brave effort from the Italian, who produced a sizzling return down the line in the final game, Azarenka sealed the win with a well-placed forehand.

Belarussian veteran Max Mirnyi captured his third US Open mixed doubles title when he and Czech Andrea Hlavackova beat American Abigail Spears and Mexican Santiago Gonzalez 7-6 (5), 6-3.

The 36-year-old Mirnyi's hat trick of wins in the event, each with different partners, was completed 15 years after his first at Flushing Meadows and was the 10th major doubles title of his career.

He partnered Serena Williams to win the US Open mixed doubles crown in 1998 and then triumphed with Victoria Azarenka in 2007.

Mirnyi's successes in the format also includes a mixed doubles Olympic gold medal that he won with Azarenka in London last year.

"Max was unbelievable, he covered 80 percent of the court and made it easy for me to make some great returns," said Hlavackova.

Hlavackova is back on court later on Friday in the women's doubles semi-finals where she and fellow Czech Lucie Hradecka face the Williams sisters.