Rangers extended their lead to four points at the top of the Scottish Premier League with an emphatic 5-0 win at Motherwell.
Following the goalless draw in the Old Firm derby last Sunday, Celtic have the upper hand in the title race, as they would overhaul Rangers if they win their two games in hand.
The Hoops play Dundee United on Sunday, but they do so knowing they cannot afford to slip up following Rangers' emphatic victory at Fir Park.
Kyle Lafferty opened the scoring for the champions, latching onto a throughball from Steven Davis, coolly rounding Darren Randolph and slotting home for his tenth goal of the season.
It remained 1-0 until the break, but Davis doubled Gers' lead in the 52nd minute with a rebound after Randolph saved Steven Naismith's initial effort. Rangers continued to look dangerous, and Nikica Jelavic made it three with a powerful header from Sasa Papac's cross.
Naismith got his name on the scoresheet with an emphatic effort from 20 yards, before another superb strike in injury time completed the rout.
Peter Pawlett climbed off the bench to net 15 minutes from time to hand Aberdeen a 1-0 win over Inverness. Pawlett struck with a powerful left-footed finish to give the Dons their first win since February.
Hearts edged closer to a Europa League place despite seeing victory snatched from their hands late on at Rugby Park by Kieran Agard's first senior goal which gave Kilmarnock a 2-2 draw.
Hearts had come back from James Fowler's brilliant opener 10 minutes into the second half when Rudi Skacel and Ryan Stevenson netted.
But on-loan Everton striker Agard volleyed home in the 86th minute as Kilmarnock capitalised on some sustained pressure.
Kevin Moon pounced on a loose ball in the box to ram home an injury-time winner as St Johnstone came from behind to beat Hibernian 2-1.
Akpo Sodje put Hibs in front after 23 minutes with his fourth goal in four games and Ricardo Vaz Te struck the post in the second half.
Substitute Liam Craig headed in Danny Grainger's 74th-minute corner as a Saints player found the net in the SPL for the first time since February 1 before Moon prodded in a 92nd-minute winner.
It was Saints' first win in almost three months, since the 2-0 defeat of Hamilton in which Stevie May struck twice, and ended a run of more than 11 games and 18 hours without an SPL goal.