In the middle of her United States Open final against Naomi Osaka at Arthur Ashe Stadium on Saturday, with a record-tying 24th Grand Slam singles title on the line, Serena Williams was standing on the court calling the chair umpire a thief.

This is not the way it was supposed to go for Williams, 36, perhaps the greatest player her sport has seen, on a night that was supposed to be a celebration of her career and her comeback to the top of tennis a year after giving birth.

After Osaka dominated the first set, another sign that this would not be a coronation for Williams came early in the second, when she received a warning for receiving help from her coach in the stands.

A few games later, Williams slammed her racket and broke it. That garnered a penalty point in Osaka’s favor. Still steaming from the previous warning, Williams fumed at the chair umpire and, as tensions rose on the court and in the crowd, she received a game penalty that gave Osaka a 5-3 lead, one game from the title.