Fresh off the back of a 2-2 Conference League draw with Shakhtar Donetsk, AZ interim manager Lee-Roy Echtold arrived in Rotterdam with a fresh starting XI after resting the bulk of his starters on Thursday. Kees Smit and Troy Parrott led the way, while captain Jordy Clasie made his first start since late September.
NEC boss Dick Schreuder left Ajax loanee Ahmetcan Kaplan on the bench in favour of a back three of Eli Dasa, Philippe Sandler, and Deveron Fonville as the Nijmegen club sought to put an end to the cup trauma that's haunted NEC after losing all five KNVB Beker finals in club history.
As is tradition in most cup finals, the match started off slowly as both sides took their time to see which way the cat jumped, eventually ending a cautious opening period when Jordy Clasie hit it on the half-volley from miles out and saw his effort smash off the crossbar in the 24th minute.
Clasie's attempt blew life into AZ, who took the reins and the lead when left-back Mees de Wit was the beneficiary of a silky Ro-Zangelo Daal dribble and tapped the ball past a mightless Jasper Cillessen in the 32nd minute.
The quality of the final dipped once more as AZ operated in a lower gear, letting NEC move up in numbers as the Alkmaar outfit were quick to hold it down tightly on defence.
Moving up in blistering tempo, Kees Smit delivered a lethal pass into NEC's box, putting Sven Mijnans in a prime position to extend AZ's lead with a clinical finish past Cillessen's near post and leave NEC with a mountain to climb with 20 minutes remaining.
Midfielder Peer Koopmeiners, brother of Juventus star Teun Koopmeiners, all but put an end to NEC's hopes of finally winning a major trophy after ruthlessly capping off a counter with a chip over Jasper Cillessen in the 73rd minute.
NEC, now pushing for any lifeline, lit the fuse on a potential comeback when substitute Koki Ogawa scored with a trademark header to give the Nijmegen side 15 minutes to at least make it to extra time.
After Tjaronn Chery made the NEC fans believe with a tricky free kick, Sven Mijnans believed he'd put the final nail in the coffin in the 85th minute, tapping a rebound into an empty net after Troy Parrott was stopped by Cillessen on the initial attempt, but the vice-captain's goal was ruled out for offside.
The actual final act came from the right foot of Kees Smit, who was left all alone and beat Cillessen with a delightful lob to effectively put an end to the KNVB Beker final in the first minute of added time
AZ made it an evening to truly never forget in the final seconds of the game, when Troy Parrott scored a shocking fifth for AZ with a deflected effort.
For the first time since 2013 and the fifth time in club history, AZ claimed the Dutch KNVB Beker, becoming the most successful club outside the Big Three (Ajax, PSV, Feyenoord) in Dutch Cup history.
NEC, meanwhile, are left to rue another lost final and extended the Dutch record with a sixth KNVB Beker final without winning the cup. They tie Northern Irish club Larne, who also lost six Irish Cup finals without ever winning one, and trail only FC Ruggell, an amateur club from Liechtenstein with 7 lost finals, as the active European clubs with the most lost domestic cup finals without ever winning the competition.