Defending Australian Open champion Victoria Azarenka has booked a place in the third round with a hard-fought win over Czech Barbora Zahlavova-Strycova.

Azarenka, the second seed, overcame the world No.84 6-1 6-4 in a match that was a lot tighter than the scoreline indicated.

The Belarusian was broken twice in the second set but managed to steady to take a 5-4 lead before serving out the match.

She will next face either Serbian Bojana Jovanovski or Austria’s Yvonne Meusburger on Saturday.

Azarenka said she felt “pretty good” after an awkward second set.

“I feel I was playing pretty well and I was glad I could close it out in two sets,” she said.

Joining Azarenka in the third round will be the woman she defeated in last year’s semi-finals, American Sloane Stephens.

Stephens lost the first set against Croatia’s Ajla Tomljanovic, but took the second and looked on track for victory at 3-0 up in the third before lightning forced players from Margaret Court Arena.

Tomljanovic rediscovered her early form, winning five straight games, but was broken when serving for the match and she eventually lost the contest 3-6 6-2 7-5.