It was admittedly at that stage pretty much game, set, match Palace – Sarr’s eighth goal in 15 appearances this season putting the gloss on an impressive Eagles display.
Mateta could have added another shortly beyond the hour-mark after – found by Sarr running the channel – slipping a finish beyond the far post from a tight angle.
A raft of substitutions from both sides saw the string from the visitors drawn, as Palace’s defensive shape nullified Alkmaar’s lengthy spells of possession.
There were two late opportunities as the game entered five minutes of injury time – and two unconvincing finishes from Mateo Chávez and Isak Jensen, in space inside the box – but Palace were truly worthy winners on the night.
Three straight wins in all competitions and another confident display at Selhurst Park. The next visitors? Brighton & Hove Albion on Sunday afternoon.
Palace: Henderson (GK), Richards, Lacroix, Guéhi, Muñoz (Clyne, 85), Hughes (Kamada, 65), Lerma, Mitchell, Sarr (Wharton, 65), Pino (Devenny, 73), Mateta (Uche, 85).
Subs: Benítez (GK), Matthews (GK), Canvot, Sosa, Esse.
AZ Alkmaar: Owusu-Oduro (GK), Dijkstra (de Wit, 62), Goes, Pentra, Chávez, Koopmeiners (Dekker, 80), Mijnans, Smit (Boogaard, 80), Patati (Jensen, 61), Parrott (Zeefuik, 74), Sadiq.
Subs: Verhulst (GK), Zoet (GK), Natali, Van Duijl, Van Duijn.
As It Happened