Scott McDonald hit a double to earn Motherwell their first Ladbrokes Premiership win of 2016 and leave Dundee United staring relegation in the face.
Stephen McManus headed home James McFadden’s free-kick on the stroke of half-time and United were left to rue a glaring miss from Blair Spittal just before McDonald converted a 72nd-minute corner.
The former Celtic striker sealed a 3-0 triumph at Tannadice with a long-range strike with 10 minutes left.
The victory moves Motherwell out of the relegation play-off place all the way up to eighth and three points off the top six, while United slipped 13 points adrift.
Motherwell manager Mark McGhee made five changes after defeat by Kilmarnock saw them slip into the bottom two having picked up just two points from a possible 18.
McFadden was handed his first start of the campaign while Louis Laing, Ben Hall, Keith Lasley and Louis Moult came into a new-look 3-4-1-2 formation.
United, who had Paul Dixon in for the absent Ryan Dow, lined up 4-1-3-2 and both sides cancelled each other out in an uneventful first half.
The hosts threatened when Guy Demel’s overhead kick deflected just wide and through Spittal’s shot, which forced Connor Ripley to push wide.
Motherwell had plenty of attacking options, with Marvin Johnson and Chris Cadden looking to get forward from wide areas, but their bold formation did not translate into chances until the final seconds of the half.
McDonald invited a foul in a dangerous area, getting his body in between Sean Dillon and the ball. McFadden curled in the free-kick and McManus got the slightest of touches to guide it into the far corner.
United should have levelled 10 minutes into the second half but Billy McKay inadvertently blocked John Rankin’s header in the goalmouth after Spittal had set him up six yards out.
McKay was immediately hauled off for Edward Ofere, who was quickly denied by Moult’s block, and Ripley then saved from Simon Murray.
The Motherwell goalkeeper had a huge let-off when he made a complete mess of dealing with Rankin’s cross. After the ensuing scramble, the ball broke kindly for Spittal but he headed off the top of the bar with the goal gaping.
McDonald punished the hosts moments later. Substitute Josh Law’s corner glanced off a United head and the Australian chested the ball down at the far post before flicking it into the roof of the net.
Eiji Kawashima made excellent stops from McDonald and Johnson but he could not prevent McDonald’s 25-yard strike bouncing into the corner of his net.