The visitors made all the running after opening the scoring in the 11th minute, Ivan Sproule's cross picked out Scott Brown who stroked home from the edge of the box.
The lead was doubled on 25 minutes when Brown burst from midfield and released Chris Killen with a reverse for the striker to sweep past Colin Meldrum.
Hibs kept sweeping forward and were rewarded with two more goals before the break.
The third came on 28 minutes when a David Murphy cross was missed by Killen, but fell kindly for Sproule to drill low into the net.
Sproule made it four five minutes before the break when he latched on to a long ball from Guillaume Beuzelin to sidefoot past Meldrum.
The home side did force a couple of saves from Zigi Malkowski as Steven McGarry tested him twice from 20 yards and David Clarkson headed over from a Brian Kerr corner.
However, Rob Jones made it five on 73 minutes when he connected with a simple header from a Kevin Thomson corner.
Motherwell did bag a consolation when McGarry smashed the ball high past Malkowski, only for Dean Shiels to make it 6-1 in the final minute.