Sam Stosur has suffered a shock first round exit from the Australian Open at the hands of Czech qualifier Karolina Pliskova.

Pliskova defeated Stosur 6-4, 7-6 to advance to the second round.

The 31-year-old Australian failed to capitalise on an underdone Pliskova, who twice called for the trainer during the match.

Once again it was unforced errors that cost Stosur, hitting 33 unforced errors in two sets, compared to just 23 winners.

Stosur's biggest weapon, her serve, also let her down at pivotal moments, with a first serve percentage of just 54 per cent.

Pliskova will face Monica Puig in the second round.