Alex Michelsen & Learner Tien: from pre-season to flying into Australian Open week two together

Long-time friends Alex Michelsen and Learner Tien joined forces to put in the hard years for their 2025 pre-season. Now, the two have combined to make quite the splash at the first major of the year.

On Saturday, the pair of SoCal natives and regular sparring partners since 2021 continued to deliver the goods at the Australian Open in earning their way through to the round of 16.

“We did pretty much every single day of off-season together. Really good to see the hard work is paying off,” Michelsen told press.

Michelsen, who ousted 11th seed Stefanos Tsitsipas in his first match at Melbourne Park, secured a second Top 20 scalp. The 20-year-old capitalized on all four of his break points against 19th seed Karen Khachanov, the 2023 semifinalist, in his 6-3, 7-6 (5), 6-2 victory. Michelsen finished with a +12 differential to improve upon his third-round showing here a year earlier.

“Only got broken only once today. In three out of five, that's very good for me,” said the world No. 42. “I've played the pressure points pretty well. Tie-break, 7-5, then I hit two winners from 5-All. I don't know where it came from. It just kind of happened.”

Tien, coming off a spellbinding four-hour, 49-minute upset over world No. 5 Daniil Medvedev that wrapped in a final-set tiebreaker just before 3 a.m. Friday and left Michelsen to concede, “I can't disclose how late I was up”, impressively had more left in the reserves than Corentin Moutet.

You look at Mensik and Fonseca and Learner, they can all hit the absolute crap out of the ball. I feel like they're all naturally better ball strikers than I am, but we're all playing pretty big. Alex Michelsen

In a clash of left-handers, Tien saved a set point in a dramatic opening tie-break en route to advancing, 7-6 (10), 6-3, 6-3. Moutet struggled with cramps early in the third set, but valiantly completed the match in a sign of respect that went both ways inside Kia Arena.

“All the best to him, wishing him a speedy recovery. I’m not sure what actually happened. I was stretching for a return and didn’t really see what was going on, then I saw him on the ground,” Tien said in an on-court interview.

“I didn’t want the match to end like that. He told me he was gonna keep trying just for me.”

The qualifier became the first 19-year-old since Rafael Nadal to reach the fourth round of the Australian Open. Upon hearing that link, Tien was quick to shrug it off.

“I don’t think I can start comparing myself to him now, but that’s really cool,” he reacted.

“This exceeded my expectations, what I was hoping for coming into this week. To be in the second week is amazing.”

Tien, the runner-up to Joao Fonseca at Decemeber’s Next Gen ATP Finals, will join Michelsen in the Top 100 for the first time when this event ends. There are currently two 19-year-olds among the Top 50, Jakub Mensik—who knocked out sixth-ranked Casper Ruud in the second round—and Shang Juncheng, winner of last September’s ATP event in Chengdu.

On where he fits into this emerging group of talent that also includes 18-year-old Fonseca and fellow 20-year-old Arthur Fils, Michelsen believes, “You look at Mensik and Fonseca and Learner, they can all hit the absolute crap out of the ball. I feel like they're all naturally better ball strikers than I am, but we're all playing pretty big. I feel like that's what you have to do to beat the big guys. You have to have a big game nowadays. The game is very quick.”

His favorite player as a kid, however? A veteran nearly twice his age with a flashy all-court game still going strong after knocking out the first Top 4 opponent in this year’s draw.

“(Gael) Monfils. Yeah, the guy's pure athlete. All the feel and circus shots,” said Michelsen. “He was incredible. I still love watching him. I always love watching him. For sure my favorite guy.”

A different kind of challenge awaits Michelsen next, as top-ranked Australian Alex de Minaur—a four-set winner over 31st seed Francisco Cerundulo—stands between him and the quarterfinals. In his three prior trips to his home major, the No. 8 seed has been tripped up at this very stage.

Tien gets a crack at the man who handed Fonseca his first defeat of 2025 on Thursday in Lorenzo Sonego, following his elimination of Fabian Marozsan. At 29, Sonego is also looking to join the Final 8 club at a major for the first time.