MELBOURNE, Australia -- Roger Federer kept his cool on a scorching hot second day at the Australian Open, starting his record 57th consecutive Grand Slam tournament with a straight-sets victory in his first competitive match in front of new coach Stefan Edberg.
Top-seeded Rafael Nadal advanced to the second round when opponent Bernard Tomic, bothered from the start by a left leg injury, retired from their match after losing the first set 6-4. Some in the capacity crowd of 15,000 at Rod Laver Arena booed lustily when Tomic indicated he could not continue.
Federer played the second match at Rod Laver Arena on Tuesday, and the temperature topped 106 degrees during his 6-4, 6-4, 6-2 win over Australian wild-card entry James Duckworth. He kept the points as short as possible and gave No. 133-ranked Duckworth only one look at a break point in the 1-hour, 46-minute match.
Asked how he handled the heat, the 32-year-old Federer said: "I'm here. I'm speaking. Actually, it's not crazy. I'm feeling OK right now."
"It was very dry, just hot, stinging sort of sun," he added later. "Depending on where you come from, it has a bigger effect on you, this type of heat. So it's very personal, and it can become just a very mental thing -- you just can't accept that it's hot."
Federer now owns the record for playing the most consecutive Grand Slam events, another milestone in a career that has already resulted in 17 major titles for the Swiss star. He said it was "great fun" to finally play in front of childhood hero Edberg, whom he hired on a part-time basis last month.
"I used to watch his matches and get inspired," Federer said, then added: "He warmed me up. ... I won!"
Nadal said he felt for Tomic, who called a medical timeout after three games and twice more before he quit.
"I know how tough is this situation, I had the same a few years ago at this tournament,'' he said. "Since the beginning, I saw a little bit he had some problems on the leg.''
He did not face a break point on his serve and took advantage of six of his 13 break-point opportunities.
No. 4-ranked Murray has played only two official matches since minor back surgery in September and said he needs to work his way into the tournament. He has reached three Australian Open finals but has yet to win the season's first major. Since hiring Ivan Lendl as coach, though, he has made his Grand Slam breakthroughs with titles at the US Open in 2012 and Wimbledon in 2013, ending droughts stretching to the 1930s for British men at the majors.
"I'm obviously more confident than I was a few years ago but I'm just lacking match practice," Murray said. "I'm desperate to try and win here. I've had a lot of near misses, I've played some of the best tennis of my career here, but it hasn't been good enough yet."
Del Potro, the 2009 US Open champion, made several unforced errors in dropping the first-set tiebreaker but cleaned up his game in the second set and controlled the rest of the three-hour match.