Gary Hooper claimed a double as Celtic reclaimed top spot in the Premier League with a comfortable 3-1 win over Hibernian.
Rangers had leapfrogged their Old Firm rivals to the summit 24 hours earlier but their lofty status was short-lived as Celtic eased to victory.
Anthony Stokes set the ball rolling before Hooper converted from the penalty spot and claimed his second shortly before half time. Liam Miller pulled a goal back from the spot before Hooper passed up the chance of a hat-trick from another penalty.
Michael Higdon, Craig Dargo and Steven Thomson were on target as St Mirren defeated Aberdeen 3-2 to extend their safety cushion at the foot of the table to 12 points.
Higdon, who struck a hat-trick in last Saturday's 3-1 win over bottom club Hamilton, netted his 15th goal of the season with a half-volley after six minutes and Dargo tucked in a 57th-minute second before Thomson scored a third after 68 minutes.
Aberdeen replied after 46 minutes when Chris Maguire's effort deflected in off Hugh Murray and Rob Milsom converted a 90th-minute strike from 25 yards, but Saints held on to record back-to-back victories for the first time this season.
Motherwell inflicted more Fir Park punishment on Dundee United with a 2-1 win to put them on the verge of a top-six place.
Just as they had done in a 3-0 Scottish Cup win over United seven days earlier, Jamie Murphy and Chris Humphrey put Motherwell on their way to victory with first-half strikes.
Johnny Russell headed United back in the game with 11 minutes left but two great late saves from Darren Randolph consigned them to their fourth loss at Fir Park this season - double the number of away defeats they have suffered elsewhere.