NEW YORK (AP) Caroline Wozniacki crashed John Isner's post-match news conference, needling her good friend for arriving late to his interview session and delaying the start of hers.
The fourth-seeded Wozniacki was in quite a hurry Tuesday, when she needed just 67 minutes to win at the U.S. Open against an opponent making her Grand Slam debut. Those sorts of lopsided victories have been rare among the top women so far in the first round.
Of the first 25 seeded players to take the court, nine lost. Half of the top 10 women are already out, counting third-seeded Maria Sharapova's withdrawal because of injury.
This comes in a year when the main spectacle is whether Serena Williams can complete the first Grand Slam since Steffi Graf in 1988. Less than two days into the tournament, fewer and fewer top rivals stand in her way.
Even with Wozniacki in the audience, Isner stated the obvious about the women's field.
''Caroline's got as good a shot as anyone. Obviously Serena is the favorite,'' the 13th-seeded American said after his own straight-set win.
Sixth-seeded Lucie Safarova, who pushed Williams to three sets in the French Open final, was upset by 37th-ranked Lesia Tsurenko earlier Tuesday. She said after losing 6-4, 6-1 that she was bothered by a strained abdominal muscle on her right side that she hurt in losing the New Haven final Saturday.
Like Wozniacki, second-seeded Simona Halep had no trouble, moving on in 47 minutes on a hot, humid day when Marina Erakovic retired in the second set. Halep was leading 6-2, 3-0.
Wozniacki, last year's U.S. Open runner-up to Williams, beat NCAA champion Jamie Loeb 6-2, 6-0. The 20-year-old Loeb earned a wild card into the draw by winning the college title as a sophomore at North Carolina.
Just four seeded women lost in the first round last year. Since the tournament started seeding 32 players in 2000, the largest number of women's seeds to fall in the opening round was 10 in 2012.
On the men's side, second-seeded Roger Federer routed Leonardo Mayer of Argentina 6-1, 6-2, 6-2 in a brisk 77 minutes. The 34th-ranked Mayer had given the 17-time Grand Slam champion trouble in their only previous meeting, when Federer saved five match points to win in three sets in Shanghai last year.
''I actually wasn't so confident yesterday and today,'' he said. ''I just felt like maybe could be one of those matches I just couldn't see it coming. So thankfully I took this match extremely serious. I thought at times almost I was taking it a bit too serious. I got that lucky in Shanghai, so that's why it was just creeping around in my mind that maybe today was going to be a bad day.''
American Donald Young rallied from down two sets and a break to stun 11th-seeded Gilles Simon. The 68th-ranked Young won 2-6, 4-6, 6-4, 6-4, 6-4 in 3 hours, 34 minutes with a packed Court 17 urging him on.
The 26-year-old Young's career has been one of extremes, a one-time teen prodigy who has stumbled through some long losing streaks as a pro. He reached his second ATP final at Delray Beach in February, dropped nine straight tour-level matches from March through August, and then upset sixth-ranked Tomas Berdych in Montreal this month.
Young had never before come back to win after losing the first two sets.
Simon had been 5-0 against Young. The Frenchman lost in the opening round for the first time in nine appearances at Flushing Meadows.
