Only some careless finishing and inspired goalkeeping from Motherwell's Graeme Smith kept it from being an embarrassing scoreline.
The hosts dominated the opening stages and Rob Jones saw an early shot blocked by Stephen Craigan, before Steven Fletcher saw an effort from a tight angle kept out by Smith's boot.
For all Hibs' early possession, Smith had very little to do in the first 25 minutes.
There was a let-off for Motherwell when Merouane Zemmama caused havoc with a run down the left but, when the ball broke to Fletcher, Motherwell had enough defenders around to block his shot.
The breakthrough finally came after 30 minutes. Scott Brown slipped a measured pass into the stride of Abdessalam Benjelloun and he rounded Smith before slotting the ball home.
Steven McGarry struck the post for Motherwell before Brown scored the second after 65 minutes, when he slipped the ball under Smith after a back-heel from Zemmama.
Jones then hit the post with a header before finding the net with a powerful header from a Kevin Thomson corner.
There was a late consolation for Motherwell when Scott McDonald scored in injury-time after a mistake by Brown.