SYDNEY (AP) - Top seed and defending champion Agnieszka Radwanska of Poland was defeated by American qualifier Bethanie Mattek-Sands 7-5, 6-3 in the second round of the Sydney International, a key warm-up tournament for the Australian Open.
Mattek-Sands, who is back on tour after a four-month layoff because of a right knee injury, lost in the first round in Brisbane last week and had to win three matches just to qualify for the main draw in Sydney.
''Very happy with it,'' Mattek-Sands said. ''I've played her a couple times and I've never beaten her, so it's probably one of the best wins of my career.''
Radwanska received treatment on her right serving shoulder during last week's Hopman Cup in Perth and said Tuesday it was still bothering her.
''Maybe a little bit, but I have good painkillers,'' Radwanska said. ''It's not a big deal, it should be all right.''
Mattek-Sands advanced to play fellow American Madison Keys, who defeated Croatian wild-card entry Ajla Tomljanovic 6-0, 3-6, 7-6 (3).
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