John Isner has served his way into the third round at the Sony Ericsson Open with a 2-6 6-3 6-4 over Nikolay Davydenko.
After Isner had comfortably held his first two service games, Davydenko won five games in a row to quickly seal the opening set.
The American settled immediately at the beginning of the second and, after claiming back-to-back love service holds, he claimed the single break in game four and went on to force a decider.
A single break was again enough in the final set, as Isner's emphatic serving kept the Russian at bay.
World number 10 Isner hit 12 aces to his opponent's three.