Arsenal turned a routine Champions League night into a brutal lesson for Bayern Munich, dismantling the German giants 3-1 at the Emirates in a match where the hosts’ substitutes made the visitors look second-rate.

Noni Madueke and Gabriel Martinelli came off the bench like men on a mission, flipping the script and exposing Bayern’s tired legs and tired ideas.

Jurrien Timber’s glancing header opened the show before teenage sensation Lennart Karl briefly threatened to spoil the party with a composed finish that stunned the home crowd.

But Arsenal’s second-half response was merciless. Madueke and Martinelli, players Bayern clearly didn’t prepare for, tore through the visitors’ shaky backline to hand Arsenal a fifth straight group victory.

Arsenal allowed Bayern to play their possession-heavy football early on, then punched first when Timber nodded in Bukayo Saka’s wicked corner.

Eberechi Eze whistled one wide, but Bayern’s equaliser was pure class: Joshua Kimmich’s sweeping ball, a deft volleyed pass, and Karl smashing beyond David Raya to silence the stands.

Saka tried to restore order with a powerful strike that Manuel Neuer palmed over, before Mikel Merino wasted a gilt-edged header from another delicious delivery.

Karl blew a huge chance one-on-one, Merino missed again, and then the chaos began. Madueke stabbed home from Riccardo Calafiori’s teasing ball, and Neuer’s ill-timed charge gifted Martinelli a walk-in goal that sealed Bayern’s first defeat of the season.

Arsenal continued their love affair with set-pieces, scoring their 10th corner goal of the season, more than anyone across Europe’s top five leagues.

Madueke finally broke a long goal drought, Martinelli kept up his flawless Champions League scoring streak, and Karl, despite losing, proved he’s Europe’s next teenage problem.

Neuer, though, looked every bit his age. Four of his 10 Champions League howlers have now come against Arsenal. Some nightmares never end.