Henri Anier marked his Scottish Premiership debut with an 83rd-minute winner as Motherwell piled more misery on Hibernian following their thrashing by Malmo.
Goalkeeper Ben Williams had saved his back four moments earlier when they were caught out by a long ball over the top for John Sutton.
But the Hibs defence, who conceded seven against the Swedes in the Europa League 10 days earlier, were unlocked by a simple headed clearance to allow the Estonian to race through and deliver an accomplished finish.
The 1-0 defeat puts Hibs boss Pat Fenlon under more pressure ahead of the derby against administration-hit Hearts at Tynecastle next Sunday.
Fenlon's problems did not end after the Malmo game with James McPake, Jordon Forster, Tim Clancy, Paul Cairney and Rowan Vine all unavailable through injury or suspension and Ryan McGivern not fit enough to start.
But centre-back Michael Nelson and striker James Collins made their debuts after signing during the week and the fit-again Fraser Mullen and Owain Tudur Jones came into the starting line-up.
Collins showed some good early movement in the lone striker role but Motherwell took control midway through the half after moving from a flat midfield to a diamond, with James McFadden given the freedom to roam behind Bob McHugh and John Sutton.
Visiting midfielder Keith Lasley got the first shot on target in the 26th minute when he fired in a left-footed effort after a one-two with Iain Vigurs and McFadden clipped a ball over the top of the Hibs defence for McHugh to run on to, but his header was two yards off target.
Motherwell dominated possession until the break and created the first chance of the second half when McFadden cut the ball back to McHugh, but the striker could not get enough power into his left-foot shot and Williams had an easy save.
Lee Hollis made his first save in the 52nd minute when he comfortably held Liam Craig's driven free-kick. Hibs soon had a better chance when they put together a string of passes and Mullen whipped in a powerful cross which Collins headed a yard wide.
Hibs were showing far more threat and Kevin Thomson had a long-range effort saved on the break before Stevie Hammell did well to prevent Craig converting Alex Harris' square pass.
Hollis then pushed Scott Robertson's well-executed first-time volley over the bar.
Motherwell made a double switch as the final 20 minutes approached when Zaine Francis-Angol and Anier replaced McFadden and McHugh, while Sam Stanton replaced Harris for Hibs.
There was little immediate impact but Hibs needed Williams to be alert to make two excellent saves with 13 minutes left.
The home side were caught out by Vigurs' ball over the top and Sutton had enough pace to get away from Nelson but Williams got down well to push his left-footed effort just past the far post.
McManus met Vigurs' resulting corner but Williams pushed his close-range header over the bar.
The Hibs defence did not heed the warning and were caught square again. McManus headed the ball clear from well inside his own half and that was enough to send Anier clear with the home back four flat-footed midway inside their half.
The Estonian kept his composure and guided a left-footed shot inside Williams' near post to send a vociferous away support home happy.