The Gers went into the game with a 1-0 advantage from the first leg at Ibrox, where Nacho Novo struck right at the death for the SPL outfit.
The home side made a blazing start and Igor Burzanovic almost levelled the aggregate scores in the opening minute, being denied from close range by Allan McGregor.
However, the Gers weathered the early storm and captain Barry Ferguson began to pull the strings in midfield, also looking dangerous from set-pieces.
Just after the half-hour mark Burzanovic brought another save from McGregor, before Dusan Andjelkovic drove a right-foot shot over from 12 yards out.
A few minutes later the home left-back tested McGregor again, but the Gers keeper was in the right place to make the block.
After the restart, Crvena Zvezda continued to force the issue in front of their passionate home fans, but Rangers held firm, with Carlos Cuellar a rock at the heart of the defence.
Just before the hour mark French striker Jean-Claude Darcheville raced clear, but drove his left-foot shot inches wide of the far post to spurn a chance to seal the tie.
Lee McCulloch then forced a smart save from Ivan Randjelovic as Walter Smith's side began to grow in confidence, but they needed McGregor to be at his best soon after to touch over an Ognjen Koroman drive.
Crvena Zvezda piled on the pressure as time ticked away, but were unable to break down a resolute Gers rearguard, who celebrated in style at the final whistle.