MELBOURNE, Australia — Alex Michelsen humorously explained that he was too engaged at the Australian Open on Saturday morning to have an extended chat with his mother in California. His reasoning was quite valid as the 20-year-old secured a victory on the court, defeating No. 19 seed Karen Khachanov with a score of 6-3, 7-6 (5), 6-2.

This win marked Michelsen’s advancement to the fourth round of a Grand Slam event for the first time and was his second triumph in less than a week over a top-20 opponent. In the opening round, he had already upset No. 11 Stefanos Tsitsipas in a four-set match.

During the post-match interview at John Cain Arena, Michelsen addressed the camera, turning to his mother, “Mom, hi! I’m sorry I only called you for a minute this morning. I had things to do. I love you. I miss you. I hope everything’s good at home.”

Next up for him is a match against either No. 8 Alex de Minaur from Australia or No. 31 Francisco Cerúndolo from Argentina, with a chance to secure a spot in the quarterfinals. “I’m going to sit back on the couch and watch tonight and see what happens,” Michelsen stated.

At 20, Michelsen is the second-youngest American male to reach this stage of the Australian Open since Andy Roddick in 2003. Notably, two years ago, Ben Shelton was roughly a month and a half younger than Michelsen is currently.

Michelsen is among a talented group of American players performing well at Melbourne Park, with six men and five women from the U.S. making it to the third round, which is a record for the tournament.

In his matches, Michelsen has taken down players who have previously excelled on the hard courts: Tsitsipas reached the final in Australia in 2023, while Khachanov made it to the semifinals that same year.

Under the guidance of Robby Ginepri, a 2005 U.S. Open semifinalist, Michelsen was successful in converting all four break points he faced against the strong-serving Khachanov, hitting a remarkable 39 winners compared to 27 unforced errors.

“I played unbelievable most of that match. I don’t know what’s going on. … I’ve never hit my forehand that well,” Michelsen shared. “I played some of my best tennis at the end.”