The home side's only goal came from an unlikely source. Full-back Alan Hutton netted with a header for only his second goal for the Ibrox club.
The home team only needed a point to make sure they qualified as group winners, so it was understandable that their start was fairly tentative.
The visitors could have taken an early lead when Gavin Rae and Brahim Hemdani left a through ball to each other, but Nenad Mirosavljevic squandered the chance.
Rangers came more into the game and from Nacho Novo's lay-off Rae struck the post with a well placed shot.
Filip Sebo was unlucky not to score when he saw two good shots blocked by Partizan keeper Nikolas Asprogenis.
Just before half-time Thomas Buffel's clever pass released Novo, but the keeper saved the striker's shot with his legs.
Rangers took the lead early in the second half. Sebo was fouled wide on the right and Novo's curling free-kick was headed into the top corner by Hutton from nearly 18 yards out.
The home side eased off after this goal and Partizan went close on several occasions.
Allan McGregor made three excellent saves to deny the visitors and somehow substitute Ljubisa Vukelja missed the target from only six yards late on.