Serbia's Novak Djokovic retired down a set and 0-3 to Argentina's Juan Martin del Potro in the Davis Cup semifinals on Sunday after aggravating the lower back injury he suffered during the U.S. Open.
On game point for del Potro, Djokovic stretched wide for a forehand and let out a painful scream before falling to the court in tears. The retirement put Argentina through to the final to face host Spain in December. Serbia won the Davis Cup last year, with Djokovic winning both of his singles matches against France in the final at Belgrade Arena.
This is only the third loss for the world No. 1 in 2011 and the second from a retirement. Djokovic retired to Andy Murray in Cincinnati with an injured shoulder, and also lost to Roger Federer in the French Open semifinals.