Alex Michelsen, a 20-year-old unseeded American, produced the biggest win of his young career with a 7-5, 6-3, 2-6, 6-4 first-round upset of 2023 Australian Open runner-up Stefanos Tsitsipas on Monday.

Stefanos Tsitsipas twice smashed his racket onto his bag as he exited the Australian Open in the first round against young American Alex Michelsen. Tsitsipas, who is enduring a miserable run of Grand Slam form,

American Alex Michelsen claimed the biggest win of his career when he stunned Stefanos Tsitsipas 7-5 6-3 2-6 6-4 in the first round of the Australian Open on Monday as the Greek 11th seed became the first major casualty at Melbourne Park.

Alex Michelsen produced the biggest win so far of his fledgling career to upset 2023 runner-up Stefanos Tsitsipas in the first round of the Australian Open, and he knew instinctively where credit was due.