Former Australian Open finalist Jo-Wilfried Tsonga overcame Alex de Minaur in Brisbane to join Daniil Medvedev, Kei Nishikori and Jeremy Chardy in the semi-finals.
Tsonga, 33, overcame the seventh-seeded rising Australian star 6-4 7-6 (7-2) in a high-quality contest to set up a meeting with Andy Murray's conqueror Daniil Medvedev on Saturday.
The former world No 4, who missed seven months of 2018 after knee surgery, looked like he'd never been away and should the Frenchman continue his fine form then he will be regarded as one of the dark horses in Melbourne when the first Grand Slam of 2019 starts on January 14.
"I expected something like this before the match - I'd seen him play a couple of times and I knew it would be tough," Tsonga said.
"We have completely different games. It was good tennis and I'm just really happy with the way I played."
Medvedev withstood the huge serving of Canadian Milos Raonic to win a brutal match 6-7 (2-7) 6-3 6-4.
Second-seeded Kei Nishikori and Jeremy Chardy had earlier progressed to Saturday's semi-finals with wins over Grigor Dimitrov and Yasutaka Uchiyama respectively.
In the women's tournament Karolina Pliskova recovered to blaze past Ajla Tomljanovic 6-1 1-6 6-1 and into the Brisbane International semi-finals.
Standing between Pliskova and a second Brisbane final in three seasons is Donna Vekic.
The Croatian had earlier dismantled last year's finalist Aliaksandra Sasnovich 6-2 6-0.
"I think today was probably one of the most perfect matches I've ever played in my career," said Vekic.
"Everything was going well for me. I was trying to be aggressive, trying to play my game and not give her time to be aggressive, because if she's on, she's on."
The other semi-final will be contested by Naomi Osaka and Lesia Tsurenko after the US Open champion managed to grind out a three-set win over Anastasija Sevastova while the Ukrainian dispatched Anett Kontaveit in straights.
We have every major tennis event covered from all angles via our website skysports.com/tennis. On the move? Head to our app for mobile devices and iPad, or follow our Twitter account @SkySportsTennis to join in the conversation.