Pitbull and Christina Aguilera had a true "A-Ha moment" at the 2013 Billboard Music Awards with 'Feel This Moment.'

Clad in their usual black (though Pit rocked a red tie), the duo were in sync sartorially and sonically. Aguilera's short dress showed off her newly svelte figure, while her smoky eyes were balanced by nude lips. (A nice change from her usual smoky eyes and bright red lipstick -- one or the other suits you better, Xtina!)

The performance was pretty typical for the fun loving pair of Pit and Aguilera. That is, until the closing verse!

The duo were joined by A-Ha frontman Morten Harket, whose iconic track 'Take On Me' Mr. 305 sampled for their hit. Harket sang the hook of his biggest hit to close out the performance, which was a delightful mix of new and old. And full disclosure? Harket seriously looks like he hasn't aged a day.