(Photo credit: Mike Frey-Imagn Images)

Two-time defending champion Aryna Sabalenka of Belarus stumbled for a moment in the first set, but went on to defeat Chinese qualifier Zhuoxuan Bai, 6-3, 6-1 to advance to the third round of the Australian Open.

Sabalenka appeared to be in cruise control, sprinting to a 5-0 first-set lead, but Bai, ranked No. 702 in the world, won three consecutive games, including a break of serve at 5-1. Bai fought off two set points in the ninth game before the four-time Grand Slam singles champion prevailed in the 40-minute first set.

Sabalenka kept the momentum, breaking Bai in the opening game of the second set and cruising in only 34 minutes.

'Tricky opponent, she really stepped in on the first set and for a moment I felt: what shall I do? She's crashing it,' said Sabalenka. 'Super happy I was able to close that set, I think it gave me a little more confidence I'm there, that my game is there. Focus step by step.'

Sabalenka got 72% of her first serves in, but did commit 21 unforced errors. She will meet either No. 28 Great Britain's Emma Radacanu or Anastasia Potapova of Russia in the third round.

In other afternoon action in sunny Melbourne, No. 12 Elina Svitolina of Ukraine knocked off Polish qualifier Linda Klimovicova, 7-5, 6-1 and No. 23 Diana Shnaider of Russia edged Australian wild card Talia Gibson, 3-6, 7-5, 6-3 in a 2-hour, 13-minute thriller.

Shnaider trailed Gibson 2-0 in the deciding set, but stormed back with three breaks to advance.

Surprisingly, Svitolina will meet Shnaider for the first time in the third round.

In other matches, Heather Baptiste defeated Australian qualifier Storm Hunter, 6-2, 6-1, and Kazakhstan's Yulia Putintseva eliminated France's Elsa Jacquemot, 6-1, 6-2.

Turkish qualifier Zeynip Sonmez, who made headlines on Monday by helping an ailing ball girl, advanced to the third round with a 6-2, 6-4 win over Hungary's Anna Bondar.

Sonmez will face Putintseva in the third round.

--Field Level Media