Benfica will return to Portugal with a commanding 2-0 lead after outclassing Nice in the first leg of their UEFA Champions League third qualifying round tie.
The Portuguese side, sharper from recent competitive action, took control after a goalless first half at the Allianz Riviera.
Franjo Ivanovic broke the deadlock in the 53rd minute, stretching to convert a pinpoint cross from Fredrik Aursnes.
Florentino then sealed the win late on with a stunning strike from distance, catching Yehvann Diouf off guard to give the visitors a strong cushion.
Nice had their moments, especially through Terem Moffi and Richard Rios, but struggled to break through a disciplined Benfica defence.
The Ligue 1 side now face a tough task to reach the Champions League for the first time since 1959/60.
Benfica, meanwhile, extended their unbeaten run in regulation to 19 matches (W13, D6) and are firmly on course for another group stage campaign after reaching the UCL knockouts in three of the last four seasons.
