Celtic wrapped up the title, which really was already theirs, with a narrow but deserved victory at Ibrox.
Goals from Henrik Larsson and Alan Thompson put the visitors two ahead before substitute Steven Thompson's late goal a header led to an anxious final few minutes for the champions elect.
After a scrappy opening with neither side able to keep possession, Celtic took the lead with a trademark goal.
Gavin Rae needlessly fouled Stilian Petrov and from Thompson's free-kick, Larsson somehow found space in a congested six-yard box to head home from close range.
Rangers did not learn their lesson and minutes later Thompson curled his free-kick narrowly wide after Craig Moore's foul on Stephen Pearson.
Celtic had a lucky escape when Michael Ball cut between Didier Agathe and Petrov, but his powerful cross deflected off Stanislav Varga before David Marshall managed to turn it on to the post.
The Celtic keeper then saved well from Alan Hutton's header before Frank De Boer's overhead shot went narrowly over.
The home side squandered their best chance to equalise just before half-time. From Stephen Hughes' cross the ball was shuttled quickly from Michael Mols to De Boer to Peter Lovenkrands, who slashed his shot wildly into the sidenetting from no more than six yards.
Rangers were pressing early in the second half with Hutton's dangerous shot deflected for a corner, before Celtic hit the home side with a sucker punch.
Larsson anticipated Zurab Khizanishvili's turn and quickly fed Pearson in front of Rangers' goal. Stefan Klos did well to block the midfleder's effort but was helpless to prevent Thompson shooting home despite Khizanishvili's attempt to clear on the line.
Moore was booked soon after for clattering into Chris Sutton from behind before the Celtic striker's effort from a Thompson free-kick came back off the bar.
Larsson was then guilty of a bad miss, allowing Klos to parry his effort before Rangers ran the changes.
Chris Burke and Thompson were introduced as the home side sought to salvage some pride.
From Burke's corner with seven minutes remaining, Thompson rose to bullet a header home from six yards.
Rangers tried everything in the last few minutes with Ball's effort looping just over.
However, Celtic were experienced enough to play out time and maintain their unbeaten record this season as well as recording their fourth victory over their bitterest rivals.