World number one Ashleigh Barty was forced to battle from a set down to book her place in the quarter-finals of the Adelaide International.
Barty, who suffered a shock early exit in Brisbane last week, looked set for another upset after dropping the opener to Anastasia Pavlyuchenkova.
The Australian hit back to level but suffered another setback when she let slip a 5-2 lead in the decider to allow the Russian to level.
Barty retained her composure to break her opponent once again and go on to wrap up a hard-fought 4-6 6-3 7-5 win.
Wimbledon champion Simona Halep marked her first singles match of the new season with a straight-sets win over Ajla Tomljanovic.
Second seed Halep broke the the local wildcard twice in each set to emerge a 6-4 7-5 winner in one hour and 36 minutes, despite suffering two breaks on her own serve.
In first round action, there were wins for seeds Aryna Sabalenka and Marketa Vondrousova over Hsieh Su-wei and Tatjana Maria respectively, while Arina Rodionova, Julia Goerges, Maria Sakkari and Bernarda Pera also advanced.
In the men's draw, British number one Dan Evans swept past Alexander Bublik to secure a place in the Adelaide International quarter-finals while Davis Cup team-mate Kyle Edmund also made progress in Auckland.
Evans, fresh from a convincing victory against Juan Londero in the first round, only needed 75 minutes to secure a 7-5 6-2 win over Bublik and book his spot in the last eight.
Kazakhstan's Bublik lost his serve to go down 5-4 in the first set but broke back for 5-5. Evans, ranked 33 in the world, responded by winning a third break point to take a 6-5 lead and then served to love to take the opener.
The second set was a more pedestrian affair for the Briton, as he won five of the first six games and served out the match. Evans will now face either third seed Andrey Rublev or Sam Querrey for a place in the semi-finals in Australia.
In first-round action in Adelaide, seventh seed Jan-Lennard Struff safely advanced with a 6-4 6-2 win over world number 94 Salvatore Caruso of Italy.
Albert Ramos-Vinolas edged out home favourite Jordan Thompson 6-4 6-7 (5) 6-3, American qualifier Tommy Paul beat Aljaz Bedene 6-4 6-4 and Alex Bolt beat French lucky loser Stephane Robert 6-4 2-6 6-0.
Meanwhile, at the Hobart International, top seed Elise Mertens advanced with a 6-1 6-1 win over Christina McHale.
Second seed Garbine Muguruza overcame China's Wang Yafan 6-1 7-5 while third seed Elena Rybakina and fourth seed Zhang Shuai also advanced.
The only seed to fall was eighth seed Caroline Garcia who was surprised 4-6 6-4 6-2 by Australian world number 129 Lizette Cabrera.