(CNN)John Isner could not keep the United States in the Davis Cup on Sunday, so it was likely small consolation that his incredible tennis milestone remained unbeaten. 

While the American lost to Andy Murray in Scotland, putting Great Britain into the quarterfinals of the prestigious teams event, halfway across the world an absorbing battle was playing out between two of South America's most bitter rivals. 

In the end it didn't come close to matching Isner's 11-hour marathon against Nicolas Mahut at Wimbledon in 2010, but the fourth rubber in the clash between Argentina and Brazil made its own piece of history. 

For six hour and 43 minutes, Leonardo Mayer and Joao Souza contested the second-longest singles match in tennis history -- and third longest of any format after a seven-hour doubles clash between Switzerland and the Czech Republic in 2013. 

Mayer eventually triumphed, after his 11th match point, winning 7-6 (7-4) 7-6 (7-5) 5-7 5-7 15-13 in front of a delirious home crowd in Buenos Aires to send the tie to a deciding rubber. 

It set the scene for Federico Delbonis to take on Brazil's Thomaz Bellucci in the decider -- with the winner to earn a clash with Novak Djokovic's Serbia, a 5-0 victor over Balkan rival Croatia. 

Delbonis had won the first set 6-3 when play was halted for the day due to bad light. The match will resume on Monday. 

Meanwhile, back in Glasgow, the British team celebrated after earning a home quarterfinal clash with France on July 17-19, the weekend after the completion of Wimbledon. 
What coutries did those competitors represent?
Switzerland and the Czech Republic