Novak Djokovic’s hopes for a second straight Australian Open title ended under a broiling sun Tuesday. With ice packs and massages failing to provide relief, third-ranked Djokovic looked increasingly woozy and had to give up while trailing 6-7 (3), 6-4, 6-2, 2-1, allowing No 7 Andy Roddick to claim a spot in the semi-finals.

The 26-year-old American will face second-ranked Roger Federer, who moved within two victories of his record-tying 14th Grand Slam by routing No 8 Juan Martin del Potro of Argentina 6-3, 6-0, 6-0. Federer, who owns a 15-2 advantage in previous matches with Roddick, ran off the last 13 games.

Djokovic said he was cramping and sore, and “didn’t really have time to recover” from his previous match, which ended at 2:26 am Monday. “Conditions were extreme today. It did affect more on me than him, as you could see,” Djokovic said. “But, you know, that was the situation. Really tried my best, but sometimes you can’t fight against your own body.”

Roddick, meanwhile, looked as fit as ever. After losing 15 pounds with a tough off-season workout regimen under new coach Larry Stefanki, he was quicker and his backhand stronger.

While the crowd in the night match was definitely pro-Federer, with Swiss flags abounding, it began backing the increasingly dispirited del Potro. But nothing could stop Federer, who won 51 of the last 65 points and finished with 38 winners to a mere nine unforced errors.

Perfect match
Everything was working for Federer, and his mix of speeds and spins was masterful. One service game in the first set summed it up — ace, backhand winner, forehand winner, volley winner, all in less than two minutes. As he served for the second, a fan shouted: “You’re perfect, Roger!”

The heat was slowly rising but wasn’t a major issue in the opening match, when Vera Zvonareva ran off 11 straight games in a 6-3, 6-0 win over 2007 Wimbledon finalist Marion Bartoli of France to reach the semi-finals for the first time in 25 majors.

Seventh-ranked Zvonareva will meet Dinara Safina, who survived 11 double-faults and 36 unforced errors to beat Australia’s Jelena Dokic 6-4, 4-6, 6-4 in a match with 11 service breaks. It’s the second straight Grand Slam semi-final for Safina, who lost to eventual champion Serena Williams at the US Open. (AP)

Bhupathi-Knowles in semi-finals
Third seeds Mahesh Bhupathi & Mark Knowles of the Bahamas struggled past the Spanish pair of Feliciano Lopez & Fernando Verdasco 6-1, 2-6, 6-4. They will take on the Austrian-Polish pairing of Oliver Marach & Lukasz Kubot for a place in the final. Mahesh and compatriot Sania Mirza will take on the Canadian pair of Aleksandra Wozniak & Daniel Nestor in the mixed doubles quarter-finals on Wednesday. US Open mixed doubles champions Leander Paes & Cara Black were dumped out in the second round at the hands of Patty Schnyder & Wesley Moodie 6-1, 7-5.