The odds on Steven Gerrard's men to win the league have been cut following Celtic's 1-0 defeat to league leaders Heart of Midlothian on Saturday.
The following day Rangers defeated St Mirren 2-0 despite playing with 10 men for a large chunk of the game.
Odds have been cut on Rangers to 5/1 from 9/1, with nearly 70 per cent of all bets on the league winner since Celtic's defeat being placed on the Govan side.
Celtic are still massive favourites to retain the league, making it eight titles in a row.
The league takes a break this weekend for Betfred Cup action before Rangers face back-to-back away fixtures at Motherwell then Celtic.
Aberdeen and Hibs are third and fourth favourites with Hearts still priced at 200/1 despite a strong start to the campaign.