Serena Williams fined $17,000 after US Open final outburst

Serena Williams has been fined $17,000 by the U.S. Tennis Association in the wake her outburst during a controversial U.S. Open final loss to Japan's Naomi Osaka.

The American star was fined for coaching, racket abuse and for verbal abuse when she accused umpire Carlos Ramos of being "a thief" during Saturday's stormy final.

Naomi Osaka won the final 6-2, 6-4 to become Japan's first ever Grand Slam singles champion and delay Williams's bid for a record-equaling 24th major title.

However, the final was overshadowed by the American's angry and tear-filled tirade in the second set.

The 36-year-old called umpire Ramos a "liar and a thief" and insisted "you owe me an apology."

"He alleged that I was cheating, and I wasn't cheating," Williams told reporters later.

It has already been dubbed "The Mother of all Meltdowns" by the New York Daily Post.