Andy Roddick "couldn't be prouder" of Mardy Fish following American's retirement

Former American tennis star Andy Roddick has paid tribute to countryman Mardy Fish, who ended his career at Flushing Meadows today with a first-round defeat at the US Open.

The 33-year-old started strongly by winning the first set against Feliciano Lopez, but after five sets, cramp got the better of him.

Once the match came to an end, Roddick, who won the US Open in 2003, tweeted: "@MardyFish hell of an effort my friend... I couldn't be prouder ..... Time for that margarita #cheers."

Fish won six career titles and his best position in the world rankings was 14th.