Top-ranked Jannik Sinner added another big title to his tremendous year, beating U.S. Open runner-up Taylor Fritz 6-4, 6-4 on Sunday for the ATP Finals trophy before his home fans — and before a final verdict is reached in his doping case.

Sinner won his first two Grand Slam titles at the Australian Open and U.S. Open in 2024 and had already clinched the year-end No. 1 ranking.

But Sinner also tested positive in two separate drug tests in March and a decision to clear him of wrongdoing was appealed by the World Anti-Doping Agency in September. A final ruling is expected from the Court of Arbitration for Sport early next year.

Sinner's explanation was that the banned performance-enhancer entered his system unintentionally through a massage from his physiotherapist, who had used a spray containing the steroid to treat his own cut finger.

Sinner maintained his recent mastery over Fritz, having also beaten the American in the U.S. Open final in September and in the group stage this week at the elite event for the year's top eight players.

By sweeping all five of his matches en route to the trophy, Sinner earned $4.8 million US — the largest winner's prize on the men's tour.

"It's the first title in Italy and it means so much to me," said Sinner, who also won the Next Gen ATP Finals — an event for the top under-20 players — in Milan in 2019. "It's something very, very, very special."

Sinner became the first Italian to win the finals and he went one step further than last year, when he lost the championship match to Novak Djokovic, who withdrew this time. And he did so without dropping a set — which was last accomplished by Ivan Lendl in 1986.

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Sinner faced a break point while serving for the first set but saved it with a big serve out wide that Fritz couldn't return. Then he served an ace — his 10th of the set — to close it out.

Another break by Sinner early in the second and the match was virtually over.

Sinner extended his winning streak to 11 matches. He's won 26 of his last 27 matches and ends the ATP season with eight titles and an overall record of 70-6.

Fritz was attempting to become the event's first American champion since Pete Sampras beat Andre Agassi in the title match 25 years ago.

Still, Fritz will rise to a career-high No. 4 in the rankings on Monday after beating No. 2 Alexander Zverev in a third-set tiebreaker in the semifinals on Saturday. That will make him the highest-ranked American man since Andy Roddick was No. 4 in August 2007.

The German duo of Kevin Krawietz and Tim Puetz beat Marcelo Arevalo and Mate Pavic 7-6 (5), 7-6 (6) to win the doubles title.