Rangers reduced the gap at the top of the Scottish football's Premier League with a 4-nil win over St Johnstone as Celtic's shock 2-nil defeat to Motherwell ended their 17-match unbeaten run.
Nikica Jelavic's fiercely drilled shot gave Rangers the lead in the fifth minute and, after missing a host of chances with his feet, Kyle Lafferty headed home a second just before the break.
St Johnstone enjoyed the bulk of possession in the second-half but it was Rangers who added to their score when Sasa Papac scored a rare goal in the 81st minute and Jelavic boosted their goal difference with a strike in injury time.
At Fir Park, Celtic failed to build on last weekend's 3-nil Old Firm derby win when goals from John Sutton at the start of either half earned Motherwell all three points as the Hoops lost for the first time since November.
The results mean the league leaders have a five point lead over Rangers, who have two games in hand, as the sides prepare to meet in Thursday's Scottish Cup fifth round replay at Celtic Park.