The United States Tennis Association apologized after playing a Nazi-era version of Germany’s national anthem before a Fed Cup match Saturday between the two countries. One German player said of the gaffe, “I’ve never felt more disrespected in my whole life.”

The incident took place in Hawaii, and it involved a local opera singer performing the first verse from “Deutschlandlied,” which was written in 1841 and is still Germany’s anthem. However, the modern version only uses the third verse, because the initial stanza, which includes “Deutschland, Deutschland uber alles, uber alles in der Welt” (“Germany, Germany, above all, above all in the world”), was used as Nazi propaganda.

“The USTA extends its sincerest apologies to the German Fed Cup team and all of its fans for the performance of an outdated national anthem prior to today’s Fed Cup competition,” the tennis body said in a statement. “In no way did we mean any disrespect. This mistake will not occur again, and the correct anthem will be performed for the remainder of this first-round tie.”

While the anthem was being performed, German players tried to sing the usual verse over it. “We were left shocked and did not know how to react,” Andrea Petkovic said.

Petkovic, who lost on Saturday to American Alison Riske, said afterward, “I thought it was the epitome of ignorance, and I’ve never felt more disrespected in my whole life, let alone in Fed Cup, and I’ve played Fed Cup for 13 years now and it is the worst thing that has ever happened to me.”

“Deutschlandlied” uses music composed by Joseph Haydn in 1797, with words written 44 years later by the poet August Heinrich Hoffmann von Fallersleben. The original intention of the lyrics was to advocate for a unified Germany, as opposed to the confederation of dozens of sovereign states that existed at the time, and the song was installed as the national anthem in 1922.

After the Nazis took power in 1933, they used the first verse to express the idea that Germany should rule over all other nations, and the song was banned in that country after World War II. In 1952, “Deutschlandlied” became the official anthem of West Germany, but only with the third verse sung, and that held through the reunification with East Germany, which had used a different anthem.

“As it was happening, obviously, we had no idea,” Riske said of Saturday’s rendition. “But news got around to us and it’s extremely unfortunate. We have nothing but respect for the German team and obviously that will not happen again.”

“Our American hosts at the Fed Cup opening in Hawaii made a mistake that should not happen,” German tennis federation chief Ulrich Klaus said in a statement. “The fact that in the year 2017 a wrong anthem can be played that is associated with the horror of the past was for players and staff and the officials present both shocking and disturbing.”

The German team’s coach, Barbara Ritter, described the episode as “an absolute scandal, a disrespectful incident and inexcusable.”

The U.S. completed its win over Germany on Sunday and will face the Czech Republic in the Fed Cup semifinals. Switzerland and Belarus will square off on the other side of the draw.