Colourful qualifier Bethanie Mattek-Sands stunned top seed and holder Agnieszka Radwanska 7-5, 6-2 on Tuesday in a first major upset at the ATP-WTA Sydney International.

It was the first time at Sydney since 1998 that the defending champion had lost in her first match, when holder Martina Hingis was beaten by Venus Williams.

After her 92-minute win, Mattek-Sands is now into the quarterfinals of the final event prior to Monday’s start of the Australian Open.

“I wanted to attack and set up points with my serve, but it’s hard against someone like Aga,” she said. “I’m trying to the best I can. I’m feeling good and getting matches in.

“Coming to Australia, you expect the heat and the sun,” she said of conditions. “But this has worked out great for me. My goal is to improve every day and build on my strengths.”

Second seed Petra Kvitova produced an easy win over Christina Mchale 6-1, 6-0. “I’m feeling much more better here than last year and the results are showing,” said the 2011 Wimbledon champion.

German fifth seed Angelique Kerber defeated Kaia Kanepi of Estonia 6-3, 6-4 to reach the last eight. Czech Lucie Safarova pulled off another shocker as she beat sixth seed Caroline Wozniacki 6-4, 7-6 (9-7).

Tomic, Cilic advance

In men’s play, 2013 winner Bernard Tomic stared with a second round win over eighth seed Marcel Granollers 6-3, 6-0.

“I had a slow start but I got some confidence after that,” said Tomic. He next plays qualifier Blaz Kavcic, who put out Jarkko Nieminen 6-4, 6-3. “He’s a good player to beat Jarkko, I’ll have to play like I did today,” said Tomic.

Croatian seventh seed Marin Cilic beat Germany’s Jan-Lennard Struff 3-6, 6-3, 6-3 while Czech Radek Stepanek defeated Australia’s Sam Groth 6-7 (6-8), 7-6 (7-5), 6-2 and Nicolas Mahut put out US qualifier Ryan Harrison 7-6 (7-2), 7-5.

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