World number six Maria Sakkari battled past Slovenia's Tamara Zidansek in three sets to reach the second round of the Adelaide International on Monday and kick off the new WTA season.
The 26-year-old Greek was kept on court for just over two hours before seeing off Zidansek 6-2, 0-6, 6-4.
Third seed Sakkari, who broke into the top 10 in November, admitted she had been well below her best as she warms up for the Australian Open later this month.
"I didn't feel great to be perfectly honest," she said.
"It wasn't a good match from my side but I found a way through it, which sometimes is enough, and I'm excited to be in the second round."
Sakkari looked to be in complete control when she won the first set, only for Zidansek to storm back and win the second to love.
The Slovenian looked the likely winner in a tough third set but at 4-5, the world number 30 made a number of unforced errors to hand the match to Sakkari.
Sakkari will now play either American Shelby Rogers or a qualifier.
Australian wildcard Priscilla Hon claimed the biggest win of her career when she beat two-time Wimbledon champion Petra Kvitova in three sets.
Hon, the world number 263, came back from a set and a break down to oust Kvitova 6-7 (4/7), 7-5, 6-2, her first win over a player inside the top 20.
The 23-year-old from Brisbane missed most of 2021 with a hip injury but showed no signs of nerves to win in two hours, 20 minutes.
US Open runner up Leylah Fernandez of Canada eased into the second round with a straight sets win over Russia's Ekaterina Alexandrova.
Fernandez, 19, was too strong for Alexandrova, winning 6-3, 6-4.
Other winners Monday included seventh seeded Elena Rybakina of Kazakhstan, a 6-4, 1-6, 6-1 winner over Australian Storm Sanders, Slovenia's Kaja Juvan, who beat Frenchwoman Chloe Paquet 6-4, 6-2, and Australian Ajla Tomljanovic, who downed Britain's Heather Watson 6-4, 7-6 (7/5).
World number one Ashleigh Barty and second-ranked Aryna Sabalenka have first-round byes.
Barty is set to play her first tournament since the US Open, after which she shut down her season to return to Australia as the pandemic raged.
The blockbuster match-up of the opening round features Paula Badosa against Victoria Azarenka in their first meeting since Indian Wells champion Badosa narrowly edged her rival in the final of the BNP Paribas Open last October.