Serena Williams had an epic meltdown live on ESPN at the US Open final, shouting at the chair umpire over a penalty and eventually spiraling into a rage that led to a larger game penalty, which resulted in a massive upset loss. It marked the third time in Williams’s US Open career that her anger led to an eventual defeat.

The penalties helped 20-year-old Naomi Osaka pull off an improbable upset of one of the dominant players in women’s tennis history. Osaka won 6-2 in the first set and started strong in the second. But that’s when chair umpire Carlos Ramos noticed Williams’s coach, Patrick Mouratoglou, making gestures toward his player. He assessed what’s called a coaching warning, which carries a point penalty.

Williams wasn’t having it. Her spiraling anger at the call, most of it seemingly at the notion that she would cheat, caused her to lose focus. ESPN videos later confirmed that the call was correct, as Mouratoglou was seen pushing both hands forward while looking at Williams. ESPN commentator Chris Evert suggested that it was a signal to come forward and play at the net.

Mouratoglou said later that he admittedly was coaching. However, he complained that every player employs it, to an extent, and to call it in a final was inappropriate.

For Williams, this latest incident recalled a 2009 problem, when she threatened to shove a ball down the throat of a lines woman who called a foot fault.  In 2011, she was called for hindrance by yelling during a point and had a raging tantrum.

After this latest screaming at the chair incident, Williams lost serve, erupting by slamming her racquet on the ground. Because of her prior warning, she was then assessed a point penalty to Osaka.

Williams was livid. “You owe me an apology,” she shouted. “I have never cheated in my life, I have a daughter and I stand for what’s right for her.”

As the match progressed, Williams continuing stewing. During a changeover, she called the chair umpire a “thief.” That led to a game penalty and put Osaka up 5-3, one away from victory.

Williams went nuclear.

“Because I’m a woman, you’re going to take this away from me?” she yelled. For a moment, there was a question on whether she would continue playing. But she continued on and eventually lost, weeping at the start of the trophy ceremony.

While online comments were split on Williams’s behavior, at least one past tennis star stepped up on her behalf.