Ally McCoist’s side headed to East End Park with 17 wins from their 17 matches on the road this season and they looked set to make it 18 when Dean Shiels gave them the lead in the 46th minute.
However, second-placed Dunfermline snatched a point when Lewis Martin equalised in the 71st minute.
Rangers head to the Championship with a total of 102 points – 39 more than the Pars – and a record of 33 wins and three draws from their 36 matches.
Lee McCulloch almost gave the visitors a perfect start when he connected with Fraser Aird’s corner to force a low save from goalkeeper Ryan Goodfellow in the early stages.
Bilel Mohsni headed wide from a similar delivery while Dunfermline threatened when Allan Smith turned sharply in the box before dragging his shot wide of Cammy Bell’s near post.
Aside from set-pieces, clear opportunities were few and far between in the first half.
Rangers enjoyed the majority of possession but Dunfermline were lining up with three centre-backs, restricting space and posing an occasional threat on the counter-attack.
After an even first half-hour, Rangers did improve as the period progressed and threatened when Jon Daly headed down Steven Smith’s cross into the path of Shiels and the midfielder hooked an effort narrowly wide on the turn.
Another Aird corner was whipped in just before the break and McCulloch headed dangerously back across the six-yard box.
Mohsni rose highest at the back post and saw his headed effort bounce off the crossbar and out to safety.
The pressure was growing and the breakthrough arrived inside a minute of the second half.
Daly chested down into the path of Nicky Law, who fought hard to keep the ball alive inside the area and dug out a shot at Goodfellow.
The goalkeeper’s parry fell into the path of Shiels and he applied the finish from close range.
Rangers fans were celebrating a second goal midway through the half when Arnold Peralta’s cross was converted by Law, only for an offside flag to deny them.
It looked like the visitors were cruising towards a routine victory, but they were stunned as Dunfermline levelled.
Alex Whittle’s corner was well directed and Martin rose well just a few yards from goal to power a downward header into the ground and past an exposed Bell.
Dunfermline were buoyed by their equaliser and Kerr Young headed narrowly wide from a free-kick as the hosts suddenly took control with the Rangers defence escaping a couple of panicky moments.
In an end-to-end finale, Aird showed pace to beat Ryan Williamson down the left and directed a cut-back into the path of Ian Black, whose shot deflected off John Potter and somehow cannoned off the post and out to safety with the goalkeeper completely beaten.