NEW YORK -- Victoria Azarenka and Serena Williams set up a replay of last year's U.S. Open final with a pair of hard-fought straight-set wins Friday.
The meeting will be their second in three weeks after Azarenka beat her U.S. rival last month for the Cincinnati, Ohio, title.
The Belarus second seed booked her spot in a second grand slam final of the season with a 6-4, 6-2 defeat of first-time semi-finalist Flavia Pennetta.
Williams, the top seed, world number one and defending champion, needed seven match points to finally subdue China's Li Na, 6-0, 6-3, winning into the final with the loss of only 16 games so far in the tournament.
Li held her serve by saving six Williams match-winners in the eighth game of the second set, an epic that lasted 14 minutes over eight deuces. Williams put an end to the upset dream by claiming victory a game later, serving out the win.
"It was tough at the end," said Williams, now into her 21st grand slam final.
"I was nervous, but I was able to close it out. I've been really focused this week and trying so hard. I'm looking forward to the final against Azarenka again."
Azarenka will be playing for her second grand slam title of 2013 after winning the Australian Open in January.
Her win in just a little more than 90 minutes was error-filled, with Italy's Pennetta holding in just one of her nine service games.
There were 13 breaks of serve in 18 games played, with Azarenka holding for the first time as she won a 10-minute game to end the final set after Pennetta saved five set points. The winner overcame six double-faults.
Azarenka overlooked much of the poor play as she celebrated victory.
"I'm so excited," said the 24-year-old, youngest by seven years of the four semi-finalists.
"It's been a long road to the final. It's an amazing feeling to come out and be in the final and be able to fight for the trophy. Giving myself another chance is a dream."
The winner called the contest "a good match with a lot of emotion. I felt I was rushing too much early in the first set. I couldn't keep the ball in play, and she stayed tough on return games. I had to keep my focus."
Azarenka advanced despite 25 unforced errors and just 15 winners. She improved to 31-1 on hard courts this season -- best on the WTA -- and is bidding to become the first woman to win Melbourne and New York in the same season since Martina Hingis in 1997.
Pennetta, the first Italian woman to break into the top 10 in 2009, was playing her first grand slam semi. She sat out last year's edition after career-threatening wrist surgery.
The 31-year-old had dropped as low as a 166th ranking and now stands 83rd. She came to the match having beaten four seeded players and without the loss of a set.
"Today I had my chance, but I didn't make it in the first set," Pennetta said.
"I was playing pretty good, but she played really well, very consistent. We didn't serve really well, both of us. But in the end she was the powerful player. It was a good fight, I think."
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