Serena Williams calls chair umpire 'thief' at US Open final

An angry Serena Williams called a chair umpire 'thief' and also accused him of sexism and treating her more harshly than men after an on-court tirade at the official during her US Open final defeat to Japan's Naomi Osaka on Sunday.

Official Carlos Ramos had cited Williams thrice for code violations during her 6-2, 6-4 loss to rising star Osaka: for getting coaching signals; for breaking her racket, which cost her a point; and for calling the chair umpire a thief, which cost her a whole game.

Meanwhile, aside the ugly incident, Naomi Osaka became the first Japanese to win a Grand Slam.