World No. 1 Iga Swiatek battled back from two breaks down in the final set to beat Danielle Collins 6-4, 3-6, 6-4 to reach the third round of the Australian Open for the fifth consecutive year on Thursday.
Alexander Zverev, the No. 6 seed on the men's side, also survived a scare, digging deep to beat Slovakian qualifier Lukas Klein 7-5, 3-6, 4-6, 7-6 (7-5), 7-6 (9-7) to advance.
Collins is ranked 62nd in the world, but she has a good record at Melbourne Park and beat Swiatek in the semifinals two years ago before losing to local favorite Ash Barty in the final.