It was business as usual for Novak Djokovic and Serena Williams at the Australian Open yesterday, even if allegations of widespread match-fixing cast a shadow over the opening day of the year's first grand slam. As the sun shone and more than 70000 fans streamed into Melbourne Park, the great and the good of tennis officialdom filed into a room in the bowels of Rod Laver Arena to defend their record on battling corruption.On the pristine blue showcourt only a few metres away, however, first Williams, then Djokovic gave notice that they had no intention of relinquishing the dominance they exerted last year.Williams proved far too strong for Italian Camila Giorgi in their first-round match. The 34-year-old American moved freely on the troublesome knee that forced her to quit the Hopman Cup two weeks ago. She won 6-4 7-5.Djokovic, who also won three grand slams last year, has not been beaten since August, a run that never looked like ending in his 115-minute clash with South Korean teenager Chung Hyeon.The 28-year-old played after the 6-3 6-2 6-4 victory, complimented his 19-year-old opponent on his game but advised him to come back and try again when he had more experience.Roger Federer barely needed to move out of first in his opening match against Georgian Nikoloz Basilashvili. The 34-year-old's 6-2 6-1 6-2 victory set him on a path he hopes will end with a first title in one of the sport's majors since he triumphed at Wimbledon in 2012.His next hurdle is Ukrainian Alexandr Dolgopolov, who should have "tricky" in his name."Dolgopolov is a different player, a different level," Federer said. "He's got the fitness, the power, the speed, tennis IQ, all that. It's going to be a big challenge."Maria Sharapova, the other former champion, eased past Japan's 21-year-old Nao Hibino 6-1 6-3.American Sloane Stephens, a semifinalist at Melbourne Park three years ago, had a bad day at the office and was sent packing by Chinese qualifier Wang Qiang.Former world No1 Caroline Wozniacki suffered a similar fate at the hands of Kazakhstan's Yulia Putintseva, and Sam Stosur, the former US Open champion, made her now traditional early exit from her home grand slam. ..