Volkswacht Bodensee - Tsitsipas sent packing in Australian Open first round

The 11th-seeded Greek, who played Novak Djokovic in the 2023 final at Melbourne Park, never looked comfortable against the 20-year-old who had him running all over the court.

Ranked 42, Michelsen powered home 7-5, 6-3, 2-6, 6-4 on John Cain Arena.

"I just tried to stay super composed out there today, I knew it was going to be a battle to the end," said the American, who scored his first win over a top-20 player at a Slam.

"My serve sort of let me down a bit in the fourth set, but super happy to get through it.

"It's all about the mindset. I came in with the proper mindset and I executed the game plan," he added.

Defeat compounded Tsitsipas's problems after a mediocre 2024 in which his ranking dropped to its current 12 from a career-high three.

He managed only one title, a repeat victory at Monte Carlo, and also suffered a first-round exit at the US Open.

Tsitsipas was hoping for a reset this year.

But his season started badly when he was beaten in his opening match at the United Cup by 77th-ranked Alexander Shevchenko and he carried that form to Melbourne.

R.Fischer--VB