Sara Errani dumped seventh seed Carla Suarez Navarro out of the Apia International.
The Italian won 6-3 6-3 in an hour and 27 minutes to join a very strong unseeded contingent in the second round in Sydney.
Home favourite Sam Stosur beat Errani's compatriot and 2015 US Open runner-up Roberta Vinci 4-6 7-5 7-5 in more than two and a half hours while there was simpler straight-sets progress for Sabine Lisicki, Anastasia Pavlyuchenkova and Ekaterina Makarova.
The two seeded players in action other than Suarez Navarro both progressed as Angelique Kerber came from a set down to beat Elina Svitolina 4-6 6-0 6-3 and Belinda Bencic saw off Mirjana Lucic-Baroni 7-6 (8/6) 1-6 6-4.
Qualifier Monica Puig beat lucky loser Magdalena Rybarikova 6-2 3-6 6-4.
Source: PA
