Novak Djokovic has won 24 Grand Slam titles, a record for a male tennis player, and been ranked world No. 1 for 428 weeks, more than any other man. Yet that didn’t stop him from suffering a shock 6-7, 3-6 defeat to Reilly Opelka of the United States at the 2025 Brisbane Open, part of the Serb’s preparations for the Australia Open.

Who is Reilly Opelka, the American who secured a shock win over Djokovic?

The likes of Taylor Fritz, Tommy Paul and Frances Tiafoe have been the stars of men’s American tennis of late, yet it is forgotten man Opelka who has produced one of the stand-out American victories in the men’s game in recent times.

Not that the 27-year-old doesn’t have his own claim to fame. Along with Croatia’s Ivo Karlovic, Opelka is tied as the tallest-ever ATP-ranked player at 6 feet 11 inches (2.11 metres).

The Michigan native went into the Brisbane Open ranked 293 in the world, although he was as high as 17 back in February 2022. Opelka, who has never gone past the fourth round of a Grand Slam, has been plagued by injury in the last two years, resulting in him sliding down the rankings.

Opelka has four professional titles to his name, all of which have come in the ATP 250 category. In August 2021, he reached the final of the Canadian Open, a Masters 1000 event, losing to Daniil Medvedev in the most high-profile match of his career…until now.

Who are the lowest-ranked players to have beaten Djokovic in his career?

Djokovic’s overall “worst” defeat came in 2010, when he lost to countryman Filip Krajinovic, ranked 319th in the world in Belgrade. On that occasion, however, the Serb only played one set, which he lost 6-4, before retiring due to breathing problems.

Opelka becomes the lowest-ranked player to have beaten the 37-year-old in a completed match, which was previously Spaniard Daniel Gimeno-Traver, a 178th-ranked qualifier, at the 2006 Barcelona Open (4-6, 6-3, 3-6).

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