Rangers’ title ambition was dealt a huge blow following a 2-1 loss at the hands of Hearts at Tynecastle on Sunday.
Ryan Kent gave the Light Blues the lead two minutes into the second-half following a beautiful counterattack, but the hosts pegged them back through Steven Naismith 10 minutes later.
An 83rd-minute goal from Liam Boyce sank Rangers, handing them their second defeat of the Scottish Premiership campaign and ending their run of six consecutive victories.
The loss means Rangers remain five points behind Celtic with a game in hand after the Hoops secured a 3-0 victory at Ross County’s expense on Saturday.