Australia's brutal January weather claimed another victim yesterday when defending champion Novak Djokovic quit midway through his Australian Open quarter-final against Andy Roddick.
"Aussie Jelena" Dokic was given every chance to again thrill home fans having been scheduled on the cool night session, but her dream run ended 6-4 4-6 6-4 at the hands of Dinara Safina.
Roger Federer compensated the night crowd with a short but extremely sweet performance, however, smashing eighth seed Juan Martin del Potro 6-3 6-0 6-0.
"Things went much better than I expected," the 13-times grand slam winner said.
"So surprising to have a score like that in the quarters of a slam," he added after the 80-minute tennis lesson.
Wilting Serb Djokovic became increasingly distressed as temperatures on court soared above 40 degrees Celsius before becoming the fourth player in 24 hours to abandon his match.
"Cramping and soreness in the whole body," the world number three said when asked why he had quit while trailing 6-7 6-4 6-2 2-1.
"Really unfortunate way to end up my Australian Open 2009 here in this way. Really tried my best, but sometimes you can't fight against your own body."
Dokic's emotionally-charged run at Melbourne Park had captured the imagination of her adopted homeland but her luck finally ran out against the in-form Safina.
The third-seeded Russian advanced to her third grand slam semi-final in eight months and stayed on course to emulate big brother Marat Safin by winning the Australian Open.
Dokic, who is ranked 187th in the world and beat three seeded players just to get to the quarter-finals, remained upbeat.
"Of course I'm disappointed," she said.
"But there are more positives than negatives. It's been a great start to 2009, I couldn't have asked for anything more."
Safina next meets fellow Russian and seventh seed Vera Zvonareva after she eased into the women's semi-finals with victory over Marion Bartoli. The Frenchwoman also wilted during the 6-3 6-0 thrashing.
The temperature dropped for the evening session but second-seed Federer was white-hot in his thrashing of del Potro.
The Argentine won just eight points in the second set and six in the third as the 27-year-old Federer advanced to his 19th successive grand slam semi-final.
Djokovic's withdrawal came 24 hours after almost half Monday's field had reached the quarter-finals when their opponents retired injured or ill.
Serena Williams, Svetlana Kuznetsova and Gilles Simon all eased to the last eight of their draws without having to complete their matches.
Gael Monfils and Zheng Jie waved Simon and Kuznetsova through by pulling out with wrist injures while women's second seed Williams advanced when Victoria Azarenka staggered off centre court in tears, off-balance and barely able to hold her racket, a victim of a virus and the heat.
Melbourne is braced for its hottest week in 100 years as meteorologists predict five consecutive days above 40 for the first time since 1908.