The writing was on the wall for Livingston, but this match was significant for Motherwell, should they finish in 7th place this season.
A win would seal Motherwell's place in the Premiership next season, and with that in mind, the Steelmen looked for an early lead.
Theo Bair would get the chance to score from the spot after Devlin handled the ball in the area, Bair slotted home to get the ball rolling.
Given his chance from the start, Sam Nicholson rifled home right before the break with a goal of the season contender.
Bair made it 15 goals from the season when he got on the end of Georgie Gent's cross, before Dan Casey made it 4-0 from a corner.
Joel Nouble scored a consolation goal that would have little say in the match. Motherwell's result leaves them two points off 7th, with Livingston six year stay in the Premiership coming to a close.