Former US Open champions Juan Martin del Potro of Argentina and Samantha Stosur of Australia rallied to win their second-round matches against tough French opponents at the Australian Open warm-up tournaments.
Del Potro beat Nicolas Mahut 1-6, 6-3, 6-4 at the Sydney International, while Stosur saved two match points and eked out a 6-4, 2-6, 7-6 win over Kristina Mladenovic at the Hobart International.
Stosur lost all three of her singles matches at the Hopman Cup team exhibition event last week and is looking for some confidence heading into her home Grand Slam at Melbourne Park, where she's never advanced past the fourth round.
"Any win's a good win, but when you've got to really tough it out and battle through a long match ... you're probably holding your nerve pretty well,'' Stosur said.
Earlier, former Wimbledon champion Petra Kvitova advanced to the semi-finals of the women's event in Sydney with a 7-6, 6-2 victory over Lucie Safarova.
Kvitova, the second seed, will play Tsvetana Pironkova in the semi-finals after the Bulgarian's 7-6 (2), 6-3 win over Sara Errani.
In other men's matches at Sydney, defending champion Bernard Tomic of Australia reached the quarter-finals with a 6-3, 4-6, 6-4 win over Blaz Kavcic of Slovenia, as did his compatriot, Marinko Matosevic, who upset third-seeded Andreas Seppi of Italy 6-3, 6-4.
In Hobart, defending champion Elena Vesnina retired from her second-round match with a back injury.
Spanish qualifier Estrella Cabeza Candela was leading the match 4-6, 6-2, 4-1 when Vesnina quit.
At the ATP's Heineken Open in Auckland, New Zealand, American wild card Jack Sock got the biggest win of his career when he beat second-seeded Tommy Hass 6-4, 6-4 in the second round.
Sock will face Roberto Batista Agut in Thursday's quarter-finals after the Spaniard beat sixth-seeded Benoit Paire of France 6-3, 6-4.
David Ferrer, the top-seed and defending champion, beat Donald Young of the US 6-7, 6-3, 6-1.
The Spaniard is seeking his fifth Auckland singles title.
Third-seeded American John Isner also progressed to the quarterfinals with a 7-6, 3-6, 6-2 win over Lucas Lacko of Slovakia.