Wimbledon champion Garbine Muguruza became the biggest casualty of the Australian Open so far when she was upset by Hsieh Su-wei in the second round.

The third seed was unable to deal with the unusual game of Hsieh in hot and windy conditions at Melbourne Park and slumped to a 7-6 (7/1) 6-2 defeat.

With the second round still to be completed, nine of the top 16 seeds have already fallen, emphasising the wide open nature of the women’s draw.

Hsieh, who plays with a two-handed slice forehand and likes to give opponents no rhythm, opened up a 5-2 lead in the first set and, although Muguruza fought back to force a tie-break, it was the player from Chinese Taipei who took it.

By midway through the second set, Muguruza looked thoroughly frustrated with herself and the game her opponent was making her play.

She dug in, breaking Hsieh when she served for the match and then saving a match point at 3-5, but two more arrived in the next game and the world number 88 took her chance, holding her arms aloft in delight and disbelief.