MELBOURNE - China's Zhang Shuai and partner Kristina Mladenovic won in straight sets on Saturday to progress to the women's doubles third round at the Australian Open.

Ninth seeds Zhang and Mladenovic beat Peyton Stearns and Luisa Stefani 6-2, 6-2 in one hour and 42 minutes at Melbourne Park on Saturday afternoon.

The Chinese-French duo were perfect in the big moments in the match, converting all four of their break point chances - as well as their first set and match points - while successfully defending all seven of Stearns and Stefani's break points.

Of those seven chances, four came in the very first game of the match - an 18-minute thriller off the serve of Zhang that went to deuce 10 times before Zhang and Mladenovic closed it out with consecutive winners.

After the marathon opening game, the rest of the set took only 34 minutes, with a Mladenovic backhand winner down the line off a second serve from Stefani converting the first set point.

Stefani's serve was again broken early in the second set for Zhang and Mladenovic to take a 3-1 lead.

Leading 4-2 with Mladenovic serving, another long game took place, with five deuces leading up to Zhang's volley winner that ended it in nine minutes.

In the next game, Mladenovic set up the first match point with a volley of her own and Zhang converted it with a forehand winner up the middle between Stearns and Stefani.

Zhang and Mladenovic hit 20 winners for the match compared to eight for their opponents.