TURIN, Italy -- Top-ranked Jannik Sinner added another big title to his tremendous year, beating US 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 US 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 US 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 -- the largest winner's prize on the men's tour.

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.

The crowd inside Inalpi Arena included multiple clusters of fans wearing orange -- a tribute to Sinner's red-and-orange hair, and how he once ate carrots during a match. There were orange carrot costumes, orange wigs, orange hats, jackets and plenty of other orange items, too.

Some fans even had carrots in their mouths.

The crowd broke into its customary chant of "Ole, Ole, Ole; Sin-ner, Sin-ner" when Sinner produced a drop-shot winner to break for a 4-3 lead in the first set.

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 has won 26 of his past 27 matches and ends the ATP season with eight titles and a 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 Monday after beating No. 2 Alexander Zverev in a third-set tiebreaker in the semifinals Saturday. That will make him the highest-ranked American man since Andy Roddick was No. 4 in August 2007.

It's the latest in a series of achievements for Fritz, whose run in New York made him the first American man to reach a Grand Slam singles final since Roddick lost to Roger Federer at Wimbledon in 2009.

At the start of the week, Fritz told The Associated Press that his "career has always been a very steady progression and just improving a little bit each year."

Sinner and Fritz will conclude their seasons representing defending champion Italy and the United States, respectively, in the Davis Cup finals, which start Tuesday in Malaga, Spain.

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.