Federer didn't have his best night but still took just under two hours to beat Davydenko in a somewhat workmanlike effort in their second-round Australian Open match, 6-3, 6-4, 6-4.
Davydenko, who like Federer is 31, is now ranked 40th in the world after roosting in the tour's top 10 almost continuously for five years starting in mid-2005. He had a spotty season last year with numerous early exits, including first-round defeats at the Australian Open, Roland Garros and Wimbledon.
But despite a lopsided career record (now 2-18) against the Swiss star, the pesky Davydenko has given Federer periodic fits over the years and that was especially true in their two previous meetings in Melbourne, both in the quarterfinals. Davydenko pushed Federer through four sets and two tiebreakers in 2006, and dissected Federer in the first set in 2010 before going into a mid-match tailspin.
Now four-time Australian Open champion Federer will run into a player who's much younger but has has a lot of psychic mileage for a 20-year-old -- Australia's 43rd-ranked Bernard Tomic, who is trying to put a troubled 2012 in the rearview and doing a good job of it so far.
The 6-foot-5 Tomic has never worn the trappings of next-big-thing very comfortably. He and his coach/father John have feuded with the Australian tennis federation regularly since Tomic emerged as a top junior. After a listless effort against Andy Roddick at the U.S. Open last year, Tomic had to answer to accusations of tanking. Last year, he had several scrapes with police and was suspended from Australia's Davis Cup team by captain Pat Rafter because of his dubious work ethic and attitude.
Tomic said he sat down with himself in the offseason and decided to stop spinning his wheels. He hasn't lost yet in 10 matches this season, including three at the exhibition Hopman Cup, a run to the title in Sydney, and two rounds here, the latest a four-set win over Germany's Daniel Brands. Tomic said he's serving as well as he ever has, but the biggest tweak is to his attitude, which he declared infused with urgency.
Federer, who has won all three of their past matches, including last year's fourth round here, said he'll be ready for a player on a good streak.
"It's nice he's been able to turn it around after a tough end of the year last year,'' Federer said. "It seems he's playing well. Obviously a difficult matchup in terms of early in the tournament.
"To me, he seems to be more of a guy that likes to be on center court, playing against the top guys, feels like he belongs there. I think it's going to be make it easier for him to play me."
It was a classically heat-drenched day at the tournament. Ambient air temperatures soared over 100 degrees by midday and stayed there, producing drama on a few courts. A late-afternoon doubles match won in straight sets by the Williams sisters was briefly halted when a spectator became ill and had to be helped out of the stands.
But the most frightening incident took place in the men's locker room after a match, when Blaz Kavcic, 25, of Slovenia collapsed, his whole body wracked with cramps, after outlasting 21-year-old Australian James Duckworth in a sapping 4-hour, 52-minute match, 3-6, 6-3, 6-4, 6-7 (3), 10-8.
Medical personnel attended to Kavcic immediately, and he recovered sufficiently to tweet a photo of himself receiving treatment. "Total physical collapse after the match," Kavcic posted. " feeling quite happy though, just don't know, because of my win or morphine." Tournament officials quickly clarified that Kavcic was actually treated with a muscle relaxant.
Duckworth suffered severe cramping in his hamstrings and quads, and said he was locking up with every sudden movement. The searing heat penetrated the soles of his sneakers, he said: "The court actually felt really hot underfoot. My feet were burning every time I pushed off to sprint.''
Sloane Stephens got a good handle on how much her game has improved in the past four years as she earned a professional if not perfect match to beat a nemesis from junior days, France's big-hitting Kristina Mladenovic, 6-4, 6-3 in the second round.
She said she's happy enough with her early-season performance that she intends to treat herself to a pair of Jimmy Choo flats and some Korean barbecue when she gets home. But she demurred on how much the shoes will set her back -- "more than five meals," she said, "and I eat a lot."
Stephens, seeded for the first time in a Grand Slam main draw (29th), said she is hopeful of climbing higher in the rankings in the next few months when she has very few points to defend. She has made herself available for Fed Cup duty in Italy and plans to play a big quartet of tournaments in Doha, Dubai, Indian Wells and Miami.
Rajeev Ram's loss to 12th seed Marin Cilic left Sam Querrey, who will take on Switzerland's Stanislas Wawrinka on Friday, as the last American man out of an original eight in the draw. Querrey, the 20th seed, advanced to the third round in non-ideal fashion as his friend Brian Baker was forced to retire early in the second set with a torn meniscus in his right knee.
Kelly Wolf, who represents Baker out of the Octagon agency, told ESPN.com that Baker flew home to Nashville on Thursday to be evaluated by his doctor.
Japan's 42-year-old Kimiko Date-Krumm continued to be a subject of fascination as she advanced to the third round of a Grand Slam for the first time in her second career. Date-Krumm, who defeated Israel's Shahar Peer 6-2, 7-5, last went this deep when she reached the 1996 Wimbledon semifinals before falling to Steffi Graf. Tired of the lifestyle, she then left the game for 12 years.
Nearly all of her contemporaries retired in the meantime, but she said a number of them have been encouraging about her recent modest success. "This morning, I met Iva Majoli, and she said, 'Good job yesterday. So keep going,' " Date-Krumm said. "Everybody say to me, 'You are crazy.' First word is always, 'You are crazy.' But they support me a lot.
"When I see Steffi, of course, she say to me, 'You should stop now and make the baby,' " Date-Krumm said, laughing.