Federer wins to reach Miami Open 4th round
In the final game, Federer smacked aces on the first three points. An ace on the next point was overturned by a replay review, and instead Krajinovic dumped the last shot into the net.
Federer finished with 14 aces and pulled away after converting only one of his first eight break-point chances.
Seeded fourth, Federer improved to 14-2 this year. He made his Miami debut 20 years ago and won the tournament in 2005, 2006 and 2017, when it was played on Key Biscayne.