Defending champ Andy Murray advances into fourth round with win

Andy Murray, whose tennis can resemble a swan dive while his body language is closer to a cannonball, glided -- and slumped -- into the U.S. Open's fourth round yesterday.

The defending champion's 7-6 (2), 6-2, 6-2 victory over Florian Mayer, a 29-year-old German ranked 47th, was far more pleasant to watch than Murray's between-points atmospherics.

Murray served so well that Mayer got a look at only two break points the entire match, and failed to convert both. Murray hit 42 winners to Mayer's 17.

But an imperfect shot or faulty tactic had Murray dropping his head, slapping his leg, gesturing and dragging himself around the court. Such self-critical emoting is not unusual with Murray, but the afternoon's wind and high humidity exacerbated his discomfort.

"I was struggling breathing for most of the match," he said. "It was tough, tough conditions."

Based in London but often training in Florida, Murray acknowledged a familiarity with hot, humid weather. "But, I mean, you can get used to something," he said, "and then if you aren't in those conditions for five weeks -- it's been 41/2 weeks since I've been in Miami -- that doesn't always stay with you."

In terms of tennis, though, he appeared to be right at home as soon as he arrived at the first-set tiebreaker, aided by repeated Mayer forehand errors and his own strong serve.

From there, Murray said, "I started the second set well. Started hitting the ball a little bit cleaner, was more aggressive after that, and finished it well."

The victory assures Murray of a fourth straight match against an unseeded player, because Uzbekistan's Denis Istomin, ranked 65th, knocked out No. 20 seed Andreas Seppi of Italy in five sets.

Not that seeding always is insight into a player's worth, as evidenced by unseeded Lleyton Hewitt's progress into the fourth round. Hewitt, the 32-year-old Australian who won the 2001 Open but had his career threatened by foot surgery and now sits at No. 66 in the rankings, came back from his four-set Friday night upset of No. 6 Juan Martin del Potro -- the 2009 Open champ -- with a 6-3, 7-6 (5), 3-6, 6-1 decision over Russia's 23-year-old Evgeny Donskoy, ranked 102nd.

That set up a Hewitt match against 31-year-old Russian Mikhail Youzhny, which Hewitt noted finally will put him against another player "from my era. At least I'll know who I'm playing," he said. "Half the draw, I don't know anymore."

That was not a complaint. Hewitt had hit for four hours with five-time Open champ Roger Federer last Monday and said he identified with Federer's continued appetite for the Grand Slam events at 32.

"The reason you're playing is for the majors," Hewitt said. "That's the reason I'm still playing." His Friday match was in Arthur Ashe Stadium, "and you never know if you're going to get an opportunity to play there again," he said.

"I love being out there in that atmosphere, soaking up every second of it." Even in the soaking humidity.