Celtic have been held to a 1-1 draw by St Johnstone in the Scottish Premier League on Tuesday as Motherwell were beaten at home.
Neil Lennon's league leaders extended their advantage at the top despite Nigel Hasselbaink cancelling out Efe Ambrose's 37th-minute opener at McDiarmid Park.
Motherwell's 1-0 loss to Dundee United means Celtic are now 19 points clear, but have played a game more than their nearest rivals.
Celtic dominated the early exchanges in Perth and took a deserved lead eight minutes before half-time through Ambrose.
The defender made it two goals in as many games, nodding in an Emilio Izaguirre cross past Alan Mannus from eight yards.
But the visitors would rue their failure to find a sealer as Hasselbaink came off the bench to level eight minutes from time.
Introduced just after the hour-mark, the Dutchman beat Thomas Rogne before curling his effort past Fraser Forster to give fifth-placed St Johnstone a point.
At Fir Park, a 17th-minute Johnny Russell goal gave Dundee United a surprise 1-0 victory over Motherwell.
Russell got on the end of a Gary Mackay-Steven pass and slipped his shot past Darren Randolph for his 12th league goal of the season, lifting Dundee United into eighth.