Bernard Tomic on his way to defeating Germany's Florian Mayer in the Sydney International. Photo: Brendan Esposito
Bernard Tomic has gained sweet revenge over German nemesis Florian Mayer to power into the quarter-finals of the Sydney International.
In his first success in four starts against Mayer, Tomic won 7-6 (7-4), 6-2 in 65 minutes to continue his unbeaten summer and book a date on Thursday with defending champion Jarkko Nieminen.
Mayer had crushed Tomic in straight sets in Australia's Davis Cup World Group play-off loss in Hamburg last September, but he was out of his league against the resurgent 20-year-old on Wednesday.
Tomic blasted 14 aces in 10 games and landed 74 per cent of first serves in a dominant display.
With American top seed John Isner, the world No.13, crashing out of the event on Wednesday, Tomic is now a warm favourite to claim his maiden tour title in Sydney.
Fellow American Ryan Harrison eliminated a wounded Isner 6-4, 6-4 in their second-round match before Isner revealed he may have to withdraw from next week's Australian Open due to a knee injury.
The 68th-ranked Harrison prevailed in one hour and 11 minutes in a controlled performance against Isner, who had been promoted to top seed after the withdrawals of French pair Jo-Wilfried Tsonga and Richard Gasquet.
Two further men's seeds pulled out injured on Wednesday.
French second seed Gilles Simon, the 2011 winner at Sydney Olympic Park, withdrew with a neck injury, handing Nieminen a far easier task against Slovakian lucky loser Ivo Klec.
The Finnish titleholder outclassed Klec 6-3, 6-1.
Czech sixth seed Radek Stepanek retired four points into his second-round match against Frenchman Julien Benneteau with a back injury.
Benneteau will face Harrison in Thursday's quarter-finals.