Roger Federer fought back from a set down to beat Australian wildcard John Millman and reach the last eight of the Brisbane International.
The Swiss, 33, recovered to seal a 4-6 6-4 6-3 win in just over two hours.
Federer, who had received a first-round bye, was broken once to lose the opening set and trailed 3-1 in the second against the world number 153.
But the top seed broke Millman twice to level the match before putting away two of four break points in the decider.
World number two Federer, warming up for the start of the Australian Open on 19 January, will face James Duckworth - another home hope - in the quarter-finals.
Duckworth was a 4-6 7-6 (7-5) 6-3 victor over Finland's Jarkko Nieminen.
In the women's draw, top seed Maria Sharapova defeated seventh-seeded Spaniard Carla Suarez Navarro 6-1 6-3 to reach the semi-finals.
The Russian will face Ukrainian Elina Svitolina, who came from a set down to knock out Germany's third seed Angelique Kerber 4-6 7-5 6-3.
The other last-four clash will be between second seed Ana Ivanovic and Uzbekistan-born American Varvara Lepchenko.
Serbian Ivanovic saw off Estonia's Kaia Kanepi 4-6 6-4 6-3, while Lepchenko beat Russia's Alla Kudryavtseva 7-5 7-5.