Andy Roddick marches on at US Open

Andy Roddick has prolonged his career by at least one more match as he defeated Fabio Fognini in the third round of the US Open.

The American, who will retire when his run at the tournament ends, broke once to take the opening set 7-5.

Fognini took control of the second with a break, but the American broke back instantly to force the tie-break.

Roddick was dominant thereafter as he swept the Italian aside 7-1 thanks to some trademark booming serves.

The third was just as tight, but this time Fognini broke late before winning the set 6-4.

Both players were tentative at the start of the fourth, but Roddick finally made the breakthrough to go 4-3 ahead.

From there he managed to hold serve twice more to seal the win 6-4 and set up a last-16 clash with Juan Martin Del Potro.