Feyenoord pulled level on points with second-placed AZ Alkmaar in the tense Eredivisie title race with a routine win at De Kuip.
Prolific on-loan striker John Guidetti's early goal gave them a half-time lead and Jordy Clasie and Jerson Cabral ensured victory before the hour mark.
The result leaves the Rotterdam giants three points behind leaders Ajax, who host De Graafschap tomorrow.
Guidetti's eighth-minute opener came after a well-worked short corner routine. Clasie worked the ball back to the Manchester City player, who fired home from 25 yards with keeper Wesley de Ruiter unsighted.
The home side dominated the first half, with Cabral shooting wide in the 16th minute and De Ruiter forced to tip over Guidetti's deflected shot moments later.
The Swedish teenager curled in a free-kick in the 37th minute which was superbly tipped over by De Ruiter, who then denied Cabral after a nice one-two with Otman Bakkal.
It took only four minutes of the second half for Feyenoord to double their lead, Kelvin Leerdam crossing from the right for Clasie to sweep the ball home.
And it was 3-0 in the 58th minute. Leerdam was again the provider for Cabral to burst into the box and finish left-footed.
Excelsior had their only real sight of goal in the 75th minute when Luigi Bruins shot wide with his left foot.
Feyenoord introduced forward Guyon Fernandez from the bench and he had the best of the chances in the closing stages but twice shot over.