Michelsen upsets Tsitsipas, Navarro outlasts Stearns in 2025 Australian Open first round

The Australian Open began on Sunday with 33 Americans in the men's and women's singles main draws. After three days of first-round play, 19 U.S. players are through to the Melbourne second round—11 men and eight women.

Twenty-year-old Alex Michelsen's upset of 11th seed Stefanos Tsitsipas was the pick of the opening wins for the Americans, while Emma Navarro's 6-7(5), 7-6(5), 7-5 victory against compatriot Peyton Stearns was among the most dramatic matches of the first round.

All 10 seeded Americans also advanced to Round 2: Taylor Fritz, Tommy Paul, Frances Tiafoe, Ben Shelton and Sebastian Korda on the men's side, and Coco Gauff, Jessica Pegula, Navarro, Danielle Collins and Madison Keys in the women's draw.

Michelsen stuns Tsitsipas

Michelsen earned the biggest win of his young career with a well-deserved 7-5, 6-3, 2-6, 6-4 result against Tsitsipas on Monday. The American's aggressive tennis kept his opponent on his heels for much of the match. When the Greek did attack, the 6-foot-4 Michelsen defended superbly and delivered several on-the-run backhand winners from his favored baseline wing.

“Probably the only other time I have played that well was against [Alex] de Minaur in Cabo last year,” Michelsen said post-match, as quoted on ATPTour.com. “I went in there and I never hit the ball cleaner in my whole life. I don’t think I played outrageously well like I did against De Minaur, but I did play very well.

“I had a set game plan and I knew what I wanted to do. The plan was specific to Stef, but when you play that well, playing that aggressively, you think to yourself that I might try this more often. I feel if I'm playing like that, it would definitely work against a lot of the guys.”

Navarro rallies past Stearns in longest career match

Navarro needed three hours, 20 minutes to edge Stearns in a dramatic first-round encounter in which she rallied from 5-3 down in the final set. In her first appearance on Rod Laver Arena, the 23-year-old prevailed on Tuesday in what was the longest match of her career and the longest women's singles match of the 2025 Aussie Open so far.

"Crazy match today," she said after the victory. "One of the more unique matches I've played in a while, I think. Definitely did not have my best stuff today. It was just relying a lot, I guess, on my grit and toughness and fight."

A semifinalist at the US Open and a quarterfinalist at Wimbledon next year, Navarro is bidding to reach the fourth round in Melbourne for the first time. Next up is a meeting with China's Wang Xiyu.