Petra Kvitova has battled her way past Francesca Schiavone despite 42 unforced errors and nine double faults.
The eighth seed was on court for just over two hours in hot temperatures in Melbourne, sealing a 6-4 2-6 6-2 triumph.
Kvitova struggled with her serve throughout the contest, but crucially managed to break her opponent twice in the opening set.
Despite a woeful 38% of her first serves landing in, it was Schiavone who dominated in the second.
The Italian was aided largely by Kvitova's inability to finish on break point, as the Czech wasted four opportunities to draw blood.
Kvitova was making a lot of errors, but was able to take control of the longer rallies.
She broke twice in the final set, which - at 6-2 - was perhaps harsh on Schiavone.
The 22-year-old could now face Laura Robson in the next round, provided that the Brit overcomes America's Melanie Oudin.
Michael Penkman
