After an outdated stanza of the German national anthem that later became associated with the Nazi regime was sung during the opening ceremonies, the U.S. took a 1-0 lead and was ahead in the other opening match in its best-of-5 Fed Cup quarterfinal Saturday.

Alison Riske beat Andrea Petkovic 7-6 (10), 6-2, and CoCo Vandeweghe led Julia Goerges 6-3, 3-1 when rain halted play.

The stanza of the anthem that was sung translates to "Germany, Germany, above all, above all in the world," which became identified with Adolf Hitler's Third Reich. The singing of the verse brought a stern response from Petkovic and an official statement of apology from the United States Tennis Association.

A similar anthem gaffe occurred in 2008 when, during an Euro Cup match between Germany and Austria, a Swiss broadcaster aired subtitles of the German anthem that featured the same Nazi-era lyrics.

'I thought it was the epitome of ignorance'

Petkovic, who was born in Bosnia, said in the German-speaking portion of her news conference that she considered walking off the court as the anthem went on.

"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," Petkovic said after her loss.

Ein Versuch der weniger emotionalen Erklärung bzgl. der gestrigen Hymnen Geschichte. Ich denke, es setzt Dinge besser in Perspektive: <a href="https://t.co/MSh3XNPpoZ">pic.twitter.com/MSh3XNPpoZ</a> —@andreapetkovic

She clarified her comments a day later, writing on Twitter that she was still emotional about her match when she was asked about the anthem directly afterward.

"It was a mistake for which the Americans apologized to us," she tweeted on Sunday. "And again, it's not the worst that ever happened to me in my LIFE. But it is the worst that happened to me in my Fed Cup life."

'In no way did we mean any disrespect': USTA

The USTA apologized in a statement after Petkovic's original comments.

"The USTA extends its sincerest apologies to the German Fed Cup team and all of its fans for the performance of an outdated national anthem prior to today's Fed Cup competition," the statement said.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

The USTA extends a sincere apology to the German Fed Cup team & fans 4 the outdated National Anthem. This mistake will not occur again. <a href="https://t.co/4LyG3ACe5u">pic.twitter.com/4LyG3ACe5u</a> —@usta

Riske was also apologetic in her news conference.

"As it was happening, obviously, we have no idea," Riske said. "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."

Following the completion of the suspended match Sunday, the sides will play reverse singles and a doubles match.