NEW YORK -- The sun was starting to set on the Billie Jean King National Tennis Center Friday, and the big three were all safely into the third round.
Novak Djokovic, Rafael Nadal and Roger Federer had won all 16 of the sets they played. Nadal, who had been scratchy in his opening match, was the beneficiary of a retirement by Nicolas Mahut with the score 6-2, 6-2. Incredibly, Djokovic has lost only three games, matching Serena Williams -- which is why they are both the overwhelming favorites here.
Andy Murray, however -- as he is sometimes wont to do -- was in the process of being thoroughly disappointing. He dropped the first two sets to The Netherlands' Robin Haase, who has never been mistaken for a major threat. Murray, of course, was the finalist here a year ago; Haase was in the second round for the first time ever.
Predictably, Haase -- who had beaten Murray in their only previous meeting -- unraveled and the great British hope ran off to a 4-0 lead in the ultimate set. It seemed to be over, but suddenly Haase was even at 4-all.
Murray survived a wild match on Louis Armstrong, in which he was both lucky and good when he needed to be, 6-7 (5), 2-6, 6-2, 6-0, 6-4 to advance to the third round.
"I felt sluggish the first few sets," Murray said in his on-court interview. "I forced myself to get to every single ball. Fifth set, I don't know what happened everything was a blur."
Murray, a boys' junior champion here in 2005, says the U.S. Open is his favorite tournament. He's been to the semifinals of all three previous majors this year, and his draw suggests he'll get there again -- if he can get by a potential quarterfinal matchup with either Juan Martin del Potro or John Isner.
His fourth-round opponent is Feliciano Lopez.
"I've had good success against him in the past, but it's a tricky match," said Murray.
Murray is 5-0 against Lopez, beating him most recently in straight sets in the Wimbledon quarterfinals.
2. Rafa dials it up: After playing a relatively long and uninspired first-round match, Rafael Nadal looked sharper in the second against Nicolas Mahut. The Frenchman, who was nursing a strained abdominal muscle, walked off after 1 hour, 21 minutes.
Would he rather be tested -- or walk off the court in 81 minutes?
"I prefer to be in the third round," Nadal said. "If I play three hours, four sets, tough match, even if I winning, we arrived here and say, 'Well, you're not playing very well.' If you win 6-2, 6-2, and that's happen, you come here, and is not enough to prepare for the next round.
"So what's best? You never know. The best thing is play very good the next match and try to be in the fourth round. The confidence is coming every day. I improved a little bit today."
Nadal's serve looked better; he won 82 percent of his first serves and was not broken.
3. Entertainment value: Novak Djokovic has been ridiculously good this season. He wrecked Carlos Berlocq Thursday night, winning the first 14 games on his way to a 6-0, 6-0, 6-2 victory.
Djokovic won all 10 of the Argentine's service games, an astounding number.
Djokovic is now 59-2 for the year and faces Nikolay Davydenko in a third-round match Saturday.
"He's been a top-five player for a couple years," Djokovic said. "I think he's underrated. If he is on a roll, if he feels the ball well, he can be very dangerous because he plays very fast."
Djokovic is so in tune with his game that he felt moved to showboat a bit against Berlocq when he sensed the crowd was losing interest in the third set. That is a definition of a professional.
At one point, he ran down a Berlocq shot and ripped it through his legs. Berlocq, who had previously switched the racket stretching for a backhand, was still holding it in his left hand. The ball whistled past him at net, and Djokovic had another highlight for this amazing season.
"We needed that in the match," said Novak the Entertainer.
4. Buy a hair: Leave it to the racy New York Post, the closest thing to those rabid tabloids of Fleet Street in London, to deliver the good stuff.
Rafael Nadal, the Post reported, visited the Julien Farel Salon on Madison Avenue earlier this week for his U.S. Open trim -- for the fifth straight year.
"He can only win," Farel said of the defending champion, "if he sees me."
Farel revealed that Rafa's fans have offered as much as $250 for some trimmings of his hair, but he has declined. Farel said he has too much respect for Nadal to sell the hair -- "even though I could make a lot."
Greg Garber is a senior writer for ESPN.com.