Los Angeles - Andrea Petkovic says she has 'never felt so disrespected' after a gaffe involving the German national anthem during their Fed Cup tie against the United States.
The Germans were upset and angry following a blunder at the opening ceremony to the World Group tie in Maui, Hawaii, on Saturday.
An American soloist sang an old version of the German anthem which leads off with a stanza considered overtly nationalist -- "Deutschland, Deutschland über alles" -- a reference to German supremacy.
Singing that version is a major 'no-no' in Germany, because of its strong links to the Nazi era, and only the third stanza of the old anthem is now in use.
Organisers apologised for the gaffe but a fuming Petkovic went on to lose to Alison Riske 7-6 (12/10), 6-2 to put the USA 1-0 up in the first singles rubber.
"I have never felt so disrespected in my life, it was an absolute effrontery and insolence, of the very worst kind," said the 29-year-old Petkovic adding that she and team-mate Julia Georges were in tears.
"It is with some distance the worst thing which has happened to me in my life, especially at the Fed Cup.
"We're in 2017 -- something like this should not happen in America.
"It is embarrassing and smacks of ignorance.
"Jule (Goerges) started to cry at once, I had tears in my eyes and was angry," she added.
"The bad thing is that this affects us, not the Americans."
Germany's team boss Barbara Rittner was horrified by the "respectless number".
"This is a real scandal and is inexcusable," said Rittner, who said she had even thought of snatching the microphone from the singer.
"I could have cried, because it is always a special moment, which gives you goosebumps, when you hear the anthem being played.
"What happened here hits us hard."
The president of the US Tennis Association, Katrina Adams, immediately apologised to Rittner in person and has said they will investigate.
"The USTA extends a sincere apology to the German Fed Cup team & fans 4 the outdated National Anthem," the US Tennis Association wrote in a tweet. "This mistake will not occur again."
The German tennis federation replied tersely, "@usta we hope so...", prompting the USTA to respond, "@DTB Tennis We can assure that it won't. Again, our sincere apologies."
The anthem gaffe cast a cloud over the German camp even before Petkovic's defeat.
After taking the first set tie-breaker, Riske roared to a 5-0 lead in the second and fought through a tense spell to seal the victory.
It gave the USA a leg up to surprise Australian Open semi-finalist CoCo Vandeweghe, who was to take on Julia Goerges in the second singles.
Vandeweghe took the first set from Goerges 6-3 and was up 3-1 in the second when Goerges slipped on a rain-slicked baseline, hurting her knee. A medical timeout coincided with a rain delay, and the match never resumed.
Play was to resume on Sunday, meaning both will be in singles action twice on the final day of the best-of-five match tie -- with Vandeweghe also slated for doubles.
The winner of the tie will face either the defending champion Czech Republic or Spain, who were level at 1-1 after day one in Ostrava.
The United States own a record 17 Fed Cup titles, but haven't won the nations tournament since 2000.