Alex de Minaur jokes that every Australian Open win adds to his and Katie Boulter's wedding budget

Success on home soil isn't the only thing motivating Alex de Minaur at this Australian Open. The top-ranked man from Down Under, through to the quarterfinals in Melbourne for the first time, has financial motivations behind every match he wins.

He's hoping to pad his and fiancée Katie Boulter's bank account in support of their upcoming wedding.

With combined on-court earnings nearing $20 million before the Australian Open event began, the two tennis players won't have to pinch pennies when it comes to their special day. But that doesn't mean that de Minaur hasn't been crunching the numbers of just how much the festivities will cost since the longtime partners got engaged in the offseason.

"When I'm on the court, and you see me so stressed out, I'm just thinking of the wedding budget," he joked with former British pro and broadcaster Laura Robson, a good friend of the couple's, after his 6-0, 7-6 (5), 6-3 win over American Alex Michelsen in Monday's fourth round.

"That's why I'm like, 'I need to win more money, I need to win more matches.' That's all that goes through my head. So now, you know what's going on inside my head."

Read more: Love pours in as Alex de Minaur and Katie Boulter announce their engagement

Boulter was seated in the stands in Rod Laver Arena to watch her beau break new ground in his eighth career Australian Open main draw on Monday night, as de Minaur finally put an end to a run for the 20-year-old American that saw him upset seeds Stefanos Tsitsipas and Karen Khachanov in the first week. After the two-hour and nine-minute match concluded, Boulter couldn't stop smiling as she shared a long hug with de Minaur's mother, Esther, who teared up at her son's latest tennis milestone.

Speaking with Jim Courier after the match, de Minaur joked that while he "[doesn't] believe in coincidences," he does "believe that when you're happy off the court, you play good tennis on the court."

He added that it "means the world" to finally get this far in Melbourne, having reached the last eight at the last three majors of 2024, and eyes a match against world No. 1 and defending champion Jannik Sinner next.

"There's nothing I want to do more than play well here in Australia," he said. "I'm glad I finally made it to the quarterfinals here, but let's go for bigger and better things.

"My whole career has been day by day' it hasn't been success overnight. I've had to keep on improving every year, little increments, little percentages here and there ... and I think it's a combination of that, a little more confidence, and the consistency always pays off at the end."