A Granit Xhaka thunderbolt clinched just a second-ever DFB-Pokal title for the reigning Bundesliga champions, who held out with 10 men for the entire second half against their valiant opponents.
Consequently, Leverkusen have followed in Bayern Munich, Borussia Dortmund, Werder Bremen, Koln and Schalke 04's footsteps as the latest team to win the Bundesliga and German Cup in one season, closing out a spectacular term in fitting fashion.
On the back of their Europa League heartache, sweeping Leverkusen changes saw Lukas Hradecky, Robert Andrich, Odilon Kossounou and Patrik Schick all return, but Kaiserslautern's top scorer Ragnar Ache was only fit enough for a place on the bench.
An early booking for the reintroduced Kossounou gave the 2. Bundesliga side plenty of encouragement early on, and Hradecky was forced into the first meaningful save in the fourth minute from a Daniel Hanslik drive.
However, Kaiserslautern's bright start was rendered meaningless in the 17th minute, when the ball broke kindly for Xhaka 25 yards from goal, and the ex-Arsenal man produced one of his trademark left-footed rockets into the top corner.
Leverkusen end 31-year DFB-Pokal drought
Xabi Alonso's men immediately went in search of the second after Xhaka's wonderful opener, but Schick and Alejandro Grimaldo both spurned opportunities for the insurance goal before disaster struck for Kossounou.
Already walking a tightrope owing to his second-minute yellow card, the centre-back was penalised again for a poor challenge on Boris Tomiak and had to take the walk of shame, leaving Leverkusen to see out the entire second 45 with 10 men.
Alonso understandably took Schick off at the break for a more defensive presence in Josip Stanisic, while Kaiserslautern boss Friedhelm Funkel bit the bullet and introduced Ache for the second period, which was briefly delayed by a firework display from the Red Devils' faithful.
Seventeen-goal Ache got stuck into the action straight away, firing one wide in the 59th minute before stinging Hradecky's palms three moments later, as 10-man Leverkusen lived dangerously.
Die Werkself wasted a glorious chance for two with 15 minutes of normal time remaining, though, as Jeremie Frimpong skipped Kaiserslautern goalkeeper Julian Krahl, but instead of seeing Florian Wirtz waiting for the tap-in, his cutback fell straight to a white shirt.
Nevertheless, Alonso's 10 men kept their structure in the short time that remained and comfortably kept Kaiserslautern at arm's length to etch their name on the DFB-Pokal trophy for the first time since 1993.