Marcus Foligno scored his third goal of the year Sunday but Rochester couldn't capitalize on eight power plays in suffering a 3-1 setback to Adirondack.
The Amerks outshot the Phantoms by a 34-16 margin, but were victimized by a shorthanded goal late in the first period for what proved to be the game winner.
Brayden McNabb picked up an assist on the Foligno goal, his fourth point of the year.
McNabb: 1A, 4 SOG
Brennan: -2, 8 SOG
Tropp: 1 SOG
Crawford: -1, 3 SOG
Kassian: -1, 1 SOG
MacKenzie: 2 SOG
Parker: 2 SOG
Losers of three straight, Rochester (3-3-2) sits one point back of Toronto for first place in the Western Conference's North Division.
The Amerks travel back to Hamilton on Thursday.