Ajla Tomljanovic has become the first Australian women since Jarmila Groth in 2011 to reach the quarterfinals of the Brisbane International.
The 25-year-old is the last surviving Australian in the women's singles draw heading and fought off a second set fightback from Brit Johanna Konta to win 6-2 7-6(2).
Tomljanovic took an early lead in the first set, going up four break points before going on to win four straight games in the second.
But being 4-0 down saw Konta fight with everything she had as she mounted a comeback.
"I did back off a little bit at 4-0, but it's only natural. I'm pretty proud of the way I fought back and still believed that I can win," Tomljanovic said.
Konta leveled the match at 4-all before breaking the Australian to lead 5-4 and had the chance to push for a third set but Tomljanovic remained calm under pressure with the crowd at Show Court 1 rallying around her.
She was able to force a tiebreak with Konta unable to find the momentum to push for the set as Tomljanovic served for the match win.
The win was important for the Aussie, who has been working trying to remove negative thoughts when down in a match.
"One match, in particular, went through my head when I was up a set and two breaks on Sevastova on grass and I completely lost it just mentally," Tomljanovic said.
"I just thought even if I lose this set, just don't lose it because I went nuts or stopped believing.
"The thoughts that come into my head are still the same. It's just how I respond to it now."
She will now face world No.5 and 2017 Champion Karolína Plíšková, who saw off Marie Bouzková 7-5 6-2 on Wednesday afternoon.