Roger Federer has secured a place in the third round at the Miami Masters with a 6-4 7-6(4) win over Ivo Karlovic.
The Swiss broke his opponent in the opening game of the match when Karlovic served up a double fault, while Federer lost just one point against his own serve in the first.
The 17-time Grand Slam champion continued to dominate his own service games in the second, but was unable to convert his only break points at 4-4.
In the tie-break, the Croatian held on in the opening exchanges, but the fifth seed edged ahead before wrapping the match up with back-to-back points from his own serve.
Federer will face either Thiemo de Bakker or Fernando Verdasco in the third round.
