Motherwell moved up to second place in the Scottish Premier League as they inflicted a shock 2-1 defeat on runaway league leaders Celtic on Wednesday.
Motherwell handed a first starting slot to prodigal son James McFadden but it was Nicky Law who inspired the Fir Park side as he set up Chris Humphrey for the opener in the 31st minute.
It took Celtic an hour to have a shot on target but they found themselves level in the 63rd minute when Georgios Samaras, who was returning from a long injury lay-off, headed past Darren Randolph.
However, Motherwell responded excellently and took the lead for the second time when Law crossed for Michael Higdon to volley high into the net at the far post.
The Glasgow giants still hold a massive 19-point lead at the top of the table but the win put Stuart McCall's side in pole position to clinch the second UEFA Champions League slot in the SPL.
Motherwell made a positive start when Keith Lasley tried his luck with an effort from 25 yards but a deflection took the pace out his shot and it was easily gathered.
Celtic almost took the lead in the 27th minute in bizarre circumstances when a dangerous cross from James Forrest came off the standing leg of Shaun Hutchinson and headed towards goal only for Randolph to pounce on it.
Motherwell take advantage
However, it was Motherwell who drew first blood in the 31st minute. Law twisted and turned on the edge of the box to get away from Victor Wanyama before driving a shot across goal.
His effort was going wide before Humphrey popped up at the back post to poke the ball high into the net for only his second goal of the season.
Celtic struggled to find a way back into the game and didn't have their first shot on target until nearly the hour mark when Commons made room for a shot but his shot lacked power and Randolph got down low to stop it.
Samaras hauled the Hoops level in the 63rd minute. Anthony Stokes played in the on-rushing Forrest who sent in a superb cross to the front post where Samaras got in front of Hutchinson to glance a header past Randolph.
The goal spurned the home side into action and Higdon fired them in front again.
A misplaced header from substitute Efe Ambrose allowed Henrik Ojamaa to release Law who got behind the Celtic defence and swung a cross to the back post where Higdon jumped to fire a superb volley into the roof of the net for his 19th of the season.
Motherwell had Randolph for keeping them ahead three minutes later when he blocked Joe Ledley's close range shot with his legs after he had connected with fellow substitute Gary Hooper's cross.
Celtic desperately looked for a way to avoid their first league defeat of 2013 and Randolph was equal to a header from Commons before getting down low to stop a drive from Forrest.
Elsewhere, Hearts slumped to second bottom with a 2-0 defeat away at St Mirren.
Inverness Caledonian Thistle remain behind Motherwell on goal difference following a goalless draw with Dundee United, Hibernian and Kilmarnock ended 2-2 and bottom club Dundee salvaged a point with a late goal in a 2-2 draw with St Johnstone.