Despite knocking out British hopeful Jack Draper in their second-round match, fans were delighted to see Alex heap praise on his girlfriend who had just beaten last year's Wimbledon finalist Karolina Pliskova.
WATCH: Alex De Minaur wins over Wimbledon crowd with sweet shout-out to Katie Boulter
Speaking on court following his victory, the 23-year-old - who was being watched in the crowds by his partner - told the BBC: "Before we talk about my match, can we just talk about Katie Boulter today? I mean, she had a pretty good win herself."
He added: "I'm extremely stoked to get this win. It was a battle out there. Jack's a hell of a competitor, hell of a talent, and he's got a very bright future ahead of him."
Sydney-born Alex and Katie, 25, have been dating for more than a year, and are both set to hit the courts again on Saturday. After their success, Alex shared a sweet selfie of the couple having some physio. "Solid day at the office," he remarked, adding a hands-in-the-air emoji.
Katie Boulter seen in the crowd at Wimbledon
They confirmed their romance on International Women's Day in 2021. Sharing a beautiful picture of themselves, Alex wrote: "Happy international women’s day!! Specially to this one, I don’t mind you." To which, Katie replied: "Guess you're OK too [love heart emoji]."
Katie recently praised her boyfriend and all the support he's shown her during tournaments. "Yeah, he's a pretty good boyfriend. He made it out to court," she said at Wimbledon.
Alex shared this selfie after their wins
"No, yeah, he's someone that I have a lot of admiration for on and off the tennis court.
"He is the epitome of a fighter, who goes out and gives their all every single day. That's what I aspire to be like. It really helps me because I can push myself; he helps me do that. I'm a very lucky girl."
She added: "He is probably one of the hardest-working guys out there. I'm very lucky to be in the position I am, that I get to see it day in, day out. I have so much respect for what he does."
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