Miami, April 6: Former World No 1 Serena Williams successfully defended her title at the WTA Sony Ericsson Open by beating fourth seeded Jelena Jankovic 6-1, 5-7, 6-3 in Saturday's final.

The 26-year-old Williams cruised through the opening set in just 28 minutes as Jankovic hit just three winners and made 11 unforced errors. The Serbian Jankovic, who has been battling a cold all week, found herself in trouble over and over again because of a weak second serve.

Jankovic rallied to take the second set 7-5 against Williams who struggled before eventually taking the third set.

Williams captured her second title of the season and the 30th of her career on Saturday.

The eighth seeded Williams also won her fifth championship here, having won last year in addition to claiming three straight titles from 2002-04.

Williams has amassed a 47-5 record during her 10 appearances at this hardcourt tournament, also finished as a runner-up in 1999 to sister Venus Williams.