Bob McHugh had opened the scoring on 15 minutes when he headed home from close range following a well-worked set-piece.
And McFadden settled the issue five minutes later. Hammell's cross was driven back across goal by Lionel Ainsworth and the Scotland forward flicked the ball into the far corner from six yards for his first goal of the season.
Livi scored with their first shot on target in injury-time when substitute Danny Denholm bundled home Martin Scott's corner but Motherwell had no more scares.
McFadden, who started up front, was one of five players brought into the Motherwell team after starting Sunday's 2-2 draw with Dundee United on the bench, with Ainsworth's first start a reward for his spectacular 35-yard equaliser.
McHugh had an early shot saved but nothing else of note had happened before the striker opened the scoring.
The goal failed to spark a change in tempo but Ainsworth came close to scoring a similar second goal for Motherwell just after the half-hour mark when he collected the ball 30 yards out and let fly but saw it flash just wide via a nick off a Livingston player.
Motherwell enjoyed a decent spell of possession and Livingston escaped a penalty claim three minutes before the break when Coll Donaldson came through the back of McFadden with a sliding tackle. Referee Brian Colvin had a lingering look and decided the centre-back had got enough of the ball, much to McFadden's disgust.
Livingston had their first real sight of goal moments later when Marc McNulty cut inside on the left but he shot well wide.
Donaldson had another let-off just after the break when he dallied on the ball inside his box and then slipped under pressure from Stuart Carswell. The midfielder played the ball across for McFadden but a timely challenge prevented the former Everton forward from getting a clean strike and Darren Jamieson grasped the ball on the line.
Livingston had a decent chance on the hour mark when Andrew Barrowman met Callum Fordyce's cross with a powerful header but Gunnar Nielsen watched it go wide.
The hosts continued to press but Talbot was shown a straight red card after a challenge that left Hammell needing treatment. The left-back, who avoided a booking for a wild first-half challenge on Carswell, got the ball as he slid straight in but Colvin deemed it reckless.
Motherwell moved quickly to press home their advantage and doubled their lead with a vintage piece of skill by McFadden.
Another McFadden back-heel set up a string of shooting chances but Jamieson made a triple save from John Sutton, Ramsden and the Scotland forward.
Jamieson saved well from Ainsworth after good wing play from substitute Craig Moore before Denholm set up an anxious few minutes for the visitors.