Motherwell produced a stunning second-half performance as they trounced relegation-threatened Ross County in Dingwall.
The visitors were gifted two first-half goals by goalkeeper Ross Laidlaw, whose two mistakes allowed Blair Spittal and Paul McGinn to score, with Simon Murray equalising for the hosts in between.
Spittal then stunned the hosts with a sensational strike into the top corner after the break, with late Davor Zdravkovski and Harry Paton strikes completing the rout.
Don Cowie's County still sit two points above the play-off place, thanks to St Johnstone's late loss at Livingston, with their top-flight status still in their own hands with just two games to go.
Motherwell's three points lift them above Hibernian and Aberdeen into seventh ahead of their game on Sunday.
Spittal’s early strike came after a succession of Motherwell chances, with Andy Halliday’s strike troubling Laidlaw.
The County keeper then failed to deal with a straightforward Liam Kelly thump down the middle of the pitch, diverting it into Spittal’s path and allowing him to slot into an empty net.
The lead was short-lived, though, as Murray raced onto an Eli King pass on the break, glanced at Kelly, and expertly slid it under the keeper.
Just as County began to dominate, Laidlaw again cost his side.
The goalkeeper charged through a group of bodies and failed to reach the ball, allowing McGinn to tap in at the back post.
The second half followed a similar pattern, with County having to wrestle control back from Motherwell as they went searching for another equaliser.
After failing to find a route back into the game - Yan Dhanda having the best of their chances - they conceded again.
Spittal let the ball roll across him onto his right foot before arrowing it spectacularly into the top corner.
That was game over and Motherwell added some gloss.
Theo Bair squared for Zdravkovski to score his first for the club from close range, before Paton passed into the net to round off a clinical second-half performance.
Player of the match - Blair Spittal (Motherwell)
A tremendous performance from Spittal. An assist and two goals, one of them a peach of a strike. He's signing off from Motherwell in style before joining Hearts.
County's home form fails them at key moment - analysis
Manager Don Cowie spoke pre-match about the importance of County's home form but, at a crucial point in their fight for survival, they lost their way.
Cowie made three changes at half-time, all attacking, but his side's periods of dominance failed to produce any clear-cut opportunities.
Late goals have been an issue for them this season, too, and they've now conceded 22 in the last 15 minutes of games - more than any other team in the league.
Conversely, Motherwell have scored 22 in the last 15 minutes, with only Celtic (25) scoring more.
The visitprs often had to endure sustained pressure but they never looked flustered, with Spittal and Bair often acting as effective outlets when needed.
What the manager said
Ross County interim manager Don Cowie reacts to defeat by Motherwell
Ross County manager Don Cowie: I'm disappointed at the way the game finished, we gifted them two goals in the first half and they punished us for that.
“At 2-1, we’re still in the game. It's just disappointed at the way we lost our discipline and when you do that against good players, they pick you off."
Motherwell manager Stuart Kettlewell: "So professional, so proud of the players, so happy with the result.
"It puts to bed the ghost we had in the 3-0 defeat here earlier in the season. It would have been very easy to go into holiday mode and just scrape a 2-1."
Motherwell manager Stuart Kettlewell reacts to defeat by Ross County
What's next?
Ross County travel to face St Johnstone on Wednesday in a season-defining game (19:45 BST), while Motherwell are at Hibernian at the same time.
