Novak Djokovic suffered a second Olympic Games defeat in the space of 24 hours when he and Nenad Zimonjic were knocked out of the men’s doubles.
The Serb pair lost 6-4, 6-4 to Brazilian fourth seeds Marcelo Melo and Bruno Soares.
World number one lost his opening round singles to Juan Martin del Potro on Sunday, a defeat which left him in floods of tears.
Del Potro stuns Djokovic in Olympics again
The 2009 US Open champion downed Djokovic 7-6 (7/4), 7-6 (7/2) in what the Argentine later described as one of his greatest victories.
The Games are probably over for the 29-year-old, unless he is nominated for the mixed doubles later on Tuesday.