Serena Williams overcame an erratic performance at the Australian Open, on Wednesday, to beat Slovenian Tamara Zidansek 6-2 6-3 and advance to the third round.

The 38-year-old American, who is bidding for a record 24th Grand Slam singles title, was hardly troubled in the first set as she broke Zidansek twice to wrap up the opener in just over half an hour.

But the 70th-ranked Zidansek put up an impressive defense in the second set, saving seven break points as an increasingly frustrated Williams racked up more than a dozen unforced errors.

Zidansek, however, could not keep up the resistance and Williams clinched the victory with a cross-court forehand winner to set up a meeting with China’s Wang Qiang.