Motherwell inflicted a third consecutive home defeat on Rangers as two first-half strikes ensured interim manager Barry Ferguson endured a painful return to Ibrox.

Luke Armstrong and Tom Sparrow's goals in the opening period were enough to earn Motherwell just their second away victory over Rangers in 61 attempts. 

It was a comedy of errors that saw the visitors take the lead with just nine minutes on the clock, with goalkeeper Jack Butland bowling the ball out to Cyriel Dessers. 

Dessers, however, lost possession cheaply, which resulted in Dan Casey seeing his tame effort spilled by Butland, which allowed Armstrong the chance to net from close range. 

The goal was initially ruled out for offside before being corrected by the VAR as the visiting striker had timed his run perfectly, but things soon got worse for Rangers. 

On the half-hour mark, Sparrow collected Callum Slattery's ball into the box before guiding a right-footed strike into the bottom right-hand corner as jeers echoed around Ibrox. 

But Dessers atoned for his earlier error nine minutes after the restart, rifling the ball home from inside the box after Ridvan Yilmaz's pass was not cleared by Motherwell. 

There was controversy late on, though, as Dessers had a second ruled out for offside, when pictures appeared inconclusive as to whether team-mate Danilo had touched the ball on its route to him.

Celtic, then, are now just three wins away from a 55th Scottish top-flight title after beating St. Mirren 5-2 in a thrilling encounter at The SMISA Stadium on Saturday. 

Jeffrey Schlupp's opener was cancelled out by Declan John's stunning free-kick, only for Arne Engels to restore Celtic's lead from the penalty spot just before the break. 

But St. Mirren refused to lie down, as Killian Phillips restored parity once more three minutes after the restart with a bouncing volley that looped over Kasper Schmeichel. 

Yang Hyun-Jun edged Brendan Rodgers' side back ahead with 22 minutes to play, with his strike sparking a late flurry from the champions-elect to seal an impressive victory. 

A brilliant breakaway goal from Daizen Maeda, who nutmegged his man before slotting past Zach Hemming, put the result beyond doubt, before Yang grabbed his second late on.