Australian Open 2025: Alex de Minaur advances to third round with 6-2 6-4 6-3 over Tristan Boyer

Alex de Minaur has leapt to the defence of under siege Australian teammate Thanasi Kokkinakis, as the top seeded Aussie put on another clinic to book a spot in the third round.

Alex de Minaur has leapt to the defence of under siege Australian teammate Thanasi Kokkinakis ahead of a third-round showdown against Argentinian powerhouse Franciso Cerundolo.

De Minaur showcased his improved 200 km/h serve on Thursday as he comfortably brushed aside American qualifier Tristan Boyer 6-2 6-4 6-3 on Rod Laver Arena.

While de Minaur said he expected fireworks against the big-hitting Cerundolo on Saturday, he backed Kokkinakis who has come under fire for playing in St Petersburg, Russia in December despite a shoulder injury.

De Minaur also pocketed $1.2 million (AUSD) for winning the Ultimate Tennis Showdown in mid-December, playing alongside Kokkinakis in the lucrative London three-day exhibition series.

Alex de Minaur defended Kokkinakis after his second round win. Picture: Angel Martinez/Getty Images for ITF

Kokkinakis has been criticised for not resting and rehabbing his shoulder over summer after bowing out of the Australian Open amid more shoulder trouble on Wednesday night.

But De Minaur said the exhibition event was unlikely to spoil his preparation and backed Kokkinakis to make the right calls for his own career.

“Ultimately everyone decides their own schedule. Whether you’re playing an exo (exhibition match) or not, you can decide to put training around it,” de Minaur said.

“I don’t know (whether) playing tournaments or playing an ‘exo’, a three-day event, is going to cause any sort of harm one way or the other.

“Thanasi, he’s a hell of a player. So much talent. He had a tough, tough loss last night where he played some incredible tennis for four hours.

“He’s shown that he can do this in Grand Slams quite often. He’s so dangerous whenever he steps out on the court.

“More than anything, we all just want him to be out there healthy, competing to his highest possible level.”

De Minaur, who is one of only two Australian men to progress through to the third round alongside Aleksander Vukic, will face a tougher test against No. 31 seed Cerundolo on Saturday.

Next week de Minaur faces a potential quarter final against defending champion Jannik Sinner if he makes it through to the final eight.

The Demon’s serve is much improved. Picture: Michael Klein

And while de Minaur reached into his trick bag at times on Thursday, pulling out a brilliant drop shot from the baseline and some ripping crosscourt winners to put away the American, it’s his faster serve that could hold the key.

A determined de Minaur said his serve packed more of a punch this year at Melbourne Park.

“Too often in the past I didn’t have enough power where I was really playing that next shot on my terms,” de Minaur said.

“Way too often I was going for 180 km/h body serve to try and get something short, but I wasn’t really hitting 210s down the T or aces here and there to give me free points.

“Ultimately that was the biggest improvement of just adding 10, 15 km/h on serve, and also trying to not jeopardise the accuracy, still hitting those spots.

“If I can do that, I’m going to hit those aces, have a high percentage of points won on first serve. It’s definitely going to make my life easier trying to hold serve.”

The Aussie will face his toughest test yet in the third round. Picture: Mark Stewart

De Minaur’s court coverage is among the best on tour, chasing down balls in the win over Boyer which others would fail to reach.

But he said he wants to be more assertive in points after a big pre-season adding strength and size.

“Get more free points on serve, that’s been a goal for a very long time,” he said.

“Yeah, higher ball speed off the ground ultimately.

“I’ve always been able to be aggressive and have that mindset, but keep reminding myself that’s the way I want to play.

“Kind of ultimately that’s come with work off the court, getting a little bit bigger and stronger. That’s definitely helped in those areas.”

Originally published as Australian Open 2025: Alex de Minaur advances to third round with 6-2 6-4 6-3 over Tristan Boyer