Motherwell were brought back down to earth after back-to-back Premiership wins when two goals in a five-minute spell gave Kilmarnock their first league win of the season.
Danny Armstrong scored one and set up the other as Killie came roaring back from Kevin van Veen's early opener.
Armstrong squeezed a low shot into the net past Liam Kelly in 71 minutes, and five minutes later his free kick found Ash Taylor to power in a header and give the hosts the lead.
Motherwell boss Stevie Hammell will be left frustrated, as his side did squander some decent chances in the Rugby Park battle.
It looked like van Veen's early opener had set Motherwell on their way to a third successive win in the Ayrshire sunshine.
But Killie hitting the bar in the first half was a warning that wasn't heeded.
Motherwell dominated the first half and were deservedly ahead through van Veen's strike.
They could have doubled that lead though with chances for Dean Cornelius and van Veen in particular guilty of wasteful finishing.
Killie showed their menace as Kyle Lafferty sent a free kick over the bar before new signing Ben Chrisene smashed a shot off the underside of the bar.
McInnes' side turned it around in the second half to give them a valuable three points.
Kilmarnock manager Derek McInnes made two changes from the side that lost at Ross County last weekend, with Aston Villa loanee Ben Chrisene and Danny Armstrong in for Joe Wright and Rory McKenzie.
Motherwell boss Stevie Hammell kept faith with the same line-up that beat Livingston 1-0 last weekend. New signing Matt Penney and young Lennon Miller - son of former Aberdeen star Lee - were on the bench.
Motherwell created the first chance inside two minutes when Kevin van Veen got a sight of goal, but keeper Sam Walker took his low shot at the second attempt.
Killie immediately raced up the park and only a superb saving tackle from Paul McGinn stopped Oli Shaw from breaking through on Liam Kelly.
Motherwell were in the mood, and in eight minutes Connor Shields made his way down the right before picking out Dean Cornelius, but he shot narrowly wide of the left post from about 12 yards.
A trip by Ricky Lamie presented Killie with a free kick just outside the box in 11 minutes but Kyle Lafferty sent his effort comfortably over.
Motherwell took the lead in 14 minutes when Callum Slattery sent van Veen through on goal and he turned Lewis Mayo inside out before dinking the ball past outrushing Walker and into the bottom right corner of the net.
Lafferty should have done better than scoop the ball over the bar in 27 minutes from a Chjrisene cross from the left.
Killie went desperately close to an equaliser in 38 minutes when a sweeping move provided space for Chrisene, but his rising shot crashed off the underside of the bar, and Lafferty fired the rebound over.
Motherwell were throwing themselves at everything Killie could batter them with at this point and in 40 minutes Shaw saw a hooked shot land wide of the left post via a deflection.
Killie nearly levelled in 47 minutes when a terrific ball over the top released Armstrong, but he flashed his shot past the left post.
A superb ball from Blair Spittal released Shields down the right in 50 minutes, but his low shot was taken at the near post by Walker.
A decent Motherwell move ended with Slattery having a go from distance but Walker was equal to it at the right post corner.
Liam Kelly gave Motherwell fans a scare in 62 minutes when he was casual at a pass-back, but flicked the ball away from lurking Lafferty in the nick of time.
But Killie drew level in 71 minutes when Murray's cross from the left picked out Armstrong found himself in the box and after his first shot was blocked, squeezed the rebound in at the left post.
Motherwell nearly regained their lead in 74 minutes when van Veen broke forward and picked out sub Ross Tierney, but his shot was palmed past the right post.
But Killie took the lead in 76 minutes when Armstrong's free kick picked out Taylor and his powerful header found the right corner of the net.
Motherwell were denied a strong penalty claim in 79 minutes when van Veen appeared to be tripped inside the box, but referee Euan Anderson wasn't interested.
Killie nearly scored a third in 83 minutes but sub Fraser Murray forced a fine save from Kelly to deny his low strike.
KILMARNOCK: Walker, Chrisene, Taylor, Mayo, Alebiosu, Armstrong (Donnelly, 85), Power, Polworth, McInroy (McKenzie, 63), Shaw (Murray, 63), Lafferty (Cameron, 76).
Subs (not used): Woods (GK), Stokes, Lyons, Wright, Sotona.
Booked: Armstrong (83), Power (90+3).
MOTHERWELL: Kelly, O'Donnell, McGinn, Solholm, Lamie, Goss, Cornelius (Morris, 58), Slattery (Maguire, 73), Spittal (Tierney, 73), Shields (Efford, 58), van Veen.
Subs (not used): Oxborough (GK), Mugabi, Johnston, Penney, Miller.
Booked: O'Donnell (19)
Referee: Euan Anderson.
Attendance: 6238.
Follow Lanarkshire Live Sport on Twitter via @LanLiveSport, like us on Facebook or find us on Instagram for the latest sports news, pictures and video.
