Second seed Andy Roddick won the NASDAQ-100 Open title on Sunday when number three Guillermo Coria of Argentina retired due to back spasms.

Roddick was leading 6-7 (7/2) 6-3 6-1 when Coria - who received treatment from trainers throughout the match - decided he could not continue in the best-of-five-sets final.

A resident of nearby Boca Raton, Roddick improved his ATP-best total to 26 match wins this season.

He claimed his second title of the year and 13th of his career.

The 21-year-old earned approximately £300,000 for his third Tennis Masters Series crown.

Coria, the first player from Argentina to reach the final here since Alberto Mancini in 1992, remains without a hardcourt title.

After missing eight months due to a knee injury, Serena Williams captured her third straight NASDAQ-100 Open title on Saturday, completing her comeback with a 6-1 6-1 thrashing of fifth-seeded Russian Elena Dementieva.