NEW YORK — At the end, and only at the end, did Serena Williams face anything resembling a challenge in her U.S. Open semifinal.
Six times she was a point from winning. Six times she failed to come through.
All that did was delay the inevitable Friday. On match point No. 7, Williams delivered a 107 mph service winner, then let out two shouts, a mixture of relief and rejoicing after a 6-0, 6-3 victory over fifth seed Li Na that put the defending champion back in the final.
"I got tight, which happens sometimes. I just needed to relax, and then when I did relax, (Na) played some good points," said Williams, who faces No. 2 Victoria Azarenka on Sunday in a rematch of last year's final. "But it was a good experience going into the next round. If I even get a match point, I'll be ready to stay calm and just to stay focused and relaxed."
Pursuing a fifth U.S. Open championship, and 17th Grand Slam title overall, Williams has been so dominant during these two weeks that the only question each time out has been how long it would take her to win, not whether she would.
"I have been really focused," Williams said. "I set some goals for myself in (each) match and am really trying to reach those goals every time."
Through 12 sets across six matches in this tournament, Williams has lost only 16 games (for context, Azarenka lost 13 in one match alone). The WTA said that's the second-lowest total of dropped games through six matches at any major in the past 25 years. Williams, 31, can become the first woman to win the U.S. Open without dropping a set since — yes, you guessed it — herself in 2008. She also did it in 2002.
For the 14th time in the Open era (since 1968) and for the first time since 2003, the top two seeds play for the title. Azarenka has lost 12 of her 15 career meetings with Williams, but she did push her to three sets a year ago in New York. This is the first time the same women play in the final two years in a row since Williams lost to sister Venus in 2001, then beat her in 2002.
Azarenka, a two-time Australian Open champion, improved to a tour-leading 31-1 on hardcourts this season by overcoming all sorts of sloppiness to beat 83rd-ranked Flavia Pennetta 6-4, 6-2. "I was rushing too much," Azarenka said. "I played well on the return games. Flavia is such a fighter. I had to really keep my focus."
Williamses out of doubles: Serena and Venus fell 6-4, 6-2 to the Czech team of Andrea Hlavackova and Lucie Hradecka in the women's semifinals in a match played shortly after Serena won her singles semifinal.
Upsets ahead? It's easy to glance at the matchups in the men's semifinals and figure Novak Djokovic and Rafael Nadal will play each other for the championship Monday.
Djokovic is seeded No. 1, Nadal No. 2. Djokovic owns six Grand Slam titles, Nadal 12. Each already has won the U.S. Open once. They've met in five major finals in all.
And their semifinal opponents today? Djokovic's 14th consecutive major semifinal — a streak that ranks second in men's history to Roger Federer's 23 — comes against No. 9 Stanlisas Wawrinka, who makes his debut at this stage of a major. Nadal plays No. 8 Richard Gasquet, who was 1-15 in fourth-round major matches until this tournament and appears in only his second major semi.
For the better part of a decade, dating to the 2005 French Open, Nadal, Djokovic, Federer and Andy Murray have combined to win 33 of the past 34 Grand Slam titles (the exception was Juan Martin del Potro's 2009 U.S. Open championship).
"In tennis, as you know, if (you) are not Roger or Rafa and Djokovic or Andy now, you don't win so many tournaments," Wawrinka said, "and you always lose."