The United States Tennis Association has apologized for a pre-match rendition of the German national anthem that included a verse associated with the Nazi era.
The error took place Saturday at the Fed Cup tournament in Hawaii before a quarterfinal match between the American Alison Riske and Germany's Andrea Petkovic.
"Deutschlandlied," or "Song of Germany," has been the country's national anthem since the 1920s, although East Germany had a different anthem during the Communist era.
The original version of the song included a verse with the words, "Deutschland, Deutschland über alles," or "Germany, Germany above all else."
The verse was dropped after World War II, during which Germany sought world domination. The remaining words emphasize "Unity, justice and freedom."
Petkovic, who was born in Bosnia, said that when the outdated verse was sung she considered walking off the court.
"I thought it was the epitome of ignorance, and I've never felt more disrespected in my whole life, let alone in Fed Cup," she said, according to the Associated Press. "And I've played Fed Cup for 13 years now and it is the worst thing that has ever happened to me."
The USTA tweeted an apology, saying the mistake would never be repeated.
In the match, Petkovic lost to Riske 7-6, 6-2.
The USTA wound up issuing a number of Twitter apologies to various people.
And Petkovic tweeted later that her initial reaction might have been too strong.
"After taking a step back and with a bit more rational, I can now assess it the way it was: A mistake, for which the Americans apologized," she tweeted.
"It is not the worst that has happened to me in my LIFE, but it is the worst thing that has happened to me in my Fed-Cup career," she added.