Novak Djokovic fought off the stifling heat and one of his Davis Cup teammates in a harder-than-expected first-round win at the US Open Tuesday. The third-seeded Serb beat countryman Viktor Troicki 6-3, 3-6, 2-6, 7-5, 6-3 in a 3-hour, 40-minute match in Arthur Ashe Stadium, where temperatures reached the upper 90s on one of the hottest days in recent memory at Flushing Meadows. Both players were wobbling around the court by the time the match was over, and shade enveloped the court, offering a bit of relief on a day when the extreme heat rules went into effect for the women – allowing them a 10-minute break if they split sets – but the men were given no such reprieve. “Somebody from the stands kept saying to me, ‘Hold on, try to hang in there,' and that's exactly what I did,” Djokovic said. No. 16 Marcos Baghdatis was the first seeded man to fall, 6-3, 2-6, 1-6, 6-4, 7-5 to Arnaud Clement of France. Fourth-seeded Jelena Jankovic needed a comeback to defeat Simona Halep of Romania 4-6, 6-4, 7-5. Next up for Jankovic is a second-round match against Mirjana Lucic, who defeated Alicia Molik 7-6 (5), 6-1. Earlier, 11th-seeded Svetlana Kuznetsova defeated 39-year-old Kimiko Date Krumm of Japan 6-2, 4-6, 6-1. Other winners Tuesday included ninth-seeded Agnieszka Radwanska, No. 18 Aravane Rezai and No. 15 Yanina Wickmayer, a semifinalist at last year's US Open. On the men's side, No. 23 Feliciano Lopez advanced but No. 24 Ernests Gulbis lost. American Mardy Fish, the 19th seed, advanced with a five-set win over Jan Hajek of the Czech Republic. The trick shot that was the highlight of Roger Federer's first-round win was most definitely real. He's even hit it before. The five-time US Open champion was up at the net Monday night when 96th-ranked Brian Dabul of Argentina lofted a lob. Federer spun around to sprint toward the baseline. A couple of steps before reaching the wall behind the court at Arthur Ashe Stadium, and with his back to the net, Federer swatted the ball between his legs. The shot landed in a corner beside Dabul, who raised his eyebrows and shrugged. “Only he can do that,” Dabul said. It was part of a remarkable 46-4 edge in winners for Federer during his 6-1, 6-4, 6-2 victory. It also was the highlight at Flushing Meadows on Day 1 of the tournament, when past US Open champions Andy Roddick, Venus Williams and Kim Clijsters all advanced, while 2001 champion Lleyton Hewitt lost in the first round at New York for the first time. The sublime bit of shotmaking was nearly identical to a back-to-the-court, through-the-legs passing winner Federer hit against Novak Djokovic in the 2009 US Open semifinals. “This one was incredible again,” Federer said. “I turned around and couldn't believe the shot landed in the corner.” Asked if Monday's shot was better than the one against Djokovic, Federer said he'd need to go to the videotape to be sure. “In terms of difficulty, maybe this one was harder, because I had the feeling I had to run a longer distance and I was further back somehow,” he said. “I had to really give the last big push at the end. I didn't have time to set it up.” Williams won titles here in 2000 and 2001, had two runner-up finishes and nothing worse than a fourth-round loss. She looked pretty impressive Monday, becoming only the fifth woman with 200 Grand Slam match wins by beating Roberta Vinci of Italy 6-4, 6-1. It was Williams' first match since a June 29 loss at Wimbledon; she missed time because of a sprained left kneecap, and landed awkwardly on that leg early in the second set. Roddick turned 28 on Monday, and after beating Stephane Robert of France 6-3, 6-2, 6-2, was asked what significance he attributes to his age. “Obviously, I know I'm probably closer to the finish than I am to the start,” he said. “But ... it's a number. I'm barely older than I was yesterday.”