Kris Boyd finally grabbed his 100th Premier League goal for Rangers as the Scottish champions claimed all three points with a 2-1 win against Dundee United.
The striker had failed to find the back of the net in the league since a win over Hibernian back on February 14 but finally reached the milestone. Nacho Novo doubled the advantage, before Damian Casalinuovo pulled a goal back for United as Rangers held on for the win.
Second-half goals from Aiden McGeady, Darren O'Dea, debutant James Forrest and Robbie Keane against Motherwell at Parkhead extended Celtic's winning run to six games with a 4-0 win.
Four minutes after the break McGeady beat 'Well keeper John Ruddy from the edge of the box with a delightful chip and in the 78th minute his cross was headed in from close range by O'Dea.
Forrest came on for McGeady and scored two minutes from time before Keane, on for Morten Rasmussen, made it four for a win which will further strengthen the case of interim boss Neil Lennon getting the manager's post on a permanent basis.
David Obua scored a dramatic late winner as Hearts stole the final Edinburgh derby of the season to reignite their faint Europa League hopes as they beat Hibernian 2-1.
Hibernian looked set to apply the coup de grace to the Jambos' European ambitions when Anthony Stokes netted his 22nd goal of the season from the penalty spot early in the second half. But visiting boss Jim Jefferies produced two inspired substitutions in Calum Elliot and Suso Santana, the latter levelling 18 minutes from time before Obua's 89th-minute winner saw Hearts close to within three points of their arch-rivals with two games remaining.
A superb Hamilton ran out 3-1 winners over Aberdeen who finished an ill-tempered match with nine men.
Flavio Paixao nodded the Accies ahead in the opening minute before a James Wesolowski header and a Simon Mensing penalty in the second half ensured the victory. Richard Foster and Zander Diamond were both shown red cards for second bookings before Derek Young scored a late consolation.
Collin Samuel's winner deepened Kilmarnock's relegation worries as St Johnstone came from behind to win 2-1 at Rugby Park.
Frazer Wright's diving header gave Killie a deserved lead but Kenny Deuchar soon headed an equaliser a minute before the break. St Johnstone took control of possession after the interval and Samuel volleyed home from 10 yards to put Kilmarnock in serious trouble.
St Mirren midfielder Stephen O'Donnell grabbed a valuable late equaliser for the 10-man visitors to boost their survival hopes and keep Falkirk bottom with a 1-1 draw.
Falkirk playmaker Scott Arfield gave the hosts the lead seconds before the break from the penalty spot after Chris Innes was red-carded for a headbutt on Brian McLean. The Bairns had looked comfortable in the second period but O'Donnell pounced just moments after goalkeeper Robert Olejnik parried Craig Dargo's shot to nod home Graham Carey's cross as the Buddies moved four points clear of the bottom.