Motherwell maintained their grip on third place in the Scottish Premiership with a resounding 4-1 win over Hearts at Fir Park.
Goals from Iain Vigurs, Lionel Ainsworth, John Sutton and James McFadden were more than enough to see off the Jambos who could only manage a second-half Callum Paterson strike in reply.
Aberdeen were less convincing in beating St Johnstone at Pittodrie, but an early Ryan Jack goal proved enough for the Dons to take the points as they look to secure second place and European football next season.
Lee Croft and Stevie May tried willfully to pull the Saints, who had Steven MacLean sent off, back in the game, but the Perthshire club were frustrated in their efforts
Ross County bounced back from their midweek defeat at Inverness by earning a draw against Partick Thistle when Richard Brittain's 14th-minute strike cancelled out Kallum Higginbotham's early opener for the Jags.
St Mirren moved into ninth place when late goals from Conor Newton and Gregg Wylde gave them victory over Kilmarnock.
Results in full Aberdeen 1-0 St Johnstone, Celtic 5-0 Inverness CT, Motherwell 4-1 Hearts, Ross County 1-1 Partick Thistle, St Mirren 2-0 Kilmarnock
