Rio de Janeiro, Feb 5 (IANS): Brazilian doubles specialist Marcelo Melo has accused World No.16 John Isner of "unprofessionalism" after the United States defeated Brazil 3-2 in a tense Davis Cup first round tie in Jacksonville, United States.

Isner, who lost his reverse singles match Sunday to Brazil's Thomaz Bellucci 6-2, 4-6, 7-6, 4-6, 3-6, complained during and after the match of the opposition fans' vocal support and use of a tambourine, Xinhua reports.

"Isner should stop crying. Our fans did nothing untoward and supported us like any other fans would," Melo wrote on Twitter Monday.

"This isn't the sort of behaviour of a professional. Our fans were doing what they should do, encouraging us from the beginning until the end."

His comments came after Isner said the visiting supporters had not shown the players the respect they deserved.

"I don't appreciate their fans at all. I think they are very rude," he said after the match.

The United States advanced to the quarterfinals when Sam Querrey recovered from a set down to defeat Thiago Alves 4-6, 6-3, 6-4, 7-6 (3) in Sunday's final rubber.