Serena Williams overcame Jennifer Capriati to take the Nasdaq-100 Open title after a mistake-ridden final in Miami.

After beating her sister Venus in the semis, Serena somehow ground out a 7-5 7-6 win against her fellow American despite committing 59 unforced errors.

Both ladies struggled to find consistency in the opening set with four breaks of serve in the first six games.

The occasion also seemed to affect the players as Williams looked nervous and Capriati allowed herself to be distracted by the unsettled crowd.

Williams composed herself the quickest despite some big hitting from her opponent and scraped through the first set 7-5.

In the second, Capriati opened up in a more aggressive mood and broke early to lead 2-0.

The ninth game, with Capriati leading 5-3, went to deuce after Williams won a thrilling rally to deny her opponent a chance to take the set.

The psychological balance appeared to tip back in Williams favour and she broke back to level at 5-5.

However, Capriati broke back immediately as Williams made a hash of several forehands.

She then survived four break points until Williams eventually claimed an epic game to take the set to a tie-break.

As the total number of unforced errors reached the century mark, Williams took the tie break 7-4 to claim her 13th career title.