Early goals at the start of each half paved the way for Rangers' first away win of the season - and condemned sorry Mansfield to their fourth successive defeat.
The Stags, who drafted in three new players just before kick-off to alleviate their injury crisis, got off to the worst possible start when they fell behind after just six minutes.
Kevin Gallen raced down the right wing and when Lee Williamson made a mess of clearing his cross Paul Furlong pounced, hooking the loose ball into the roof of the net.
Six minutes later Mansfield should have levelled, but after wriggling clear in the area Liam Lawrence saw his low drive pushed around the post by the diving Simon Royce.
In a spirited fightback the home side twice went close to an equaliser in the 16th minute. First Wayne Corden's dipping cross-shot was tipped over by Royce who then reacted quickly to block Andy White's acrobatic overhead kick from the following corner.
Six minutes before half time White was again thwarted by the keeper's bravery when Royce saved at his feet after a jinking run from Iyseden Christie.
Then three minutes before half time Lawrence's terrific snap-shot was well blocked by the busy keeper.
Rangers continued to look dangerous on the break however and Tommy Williams twice went close from long range before Marc Bircham's 30-yard screamer was turned over by Kevin Pilkington's fingertips.
The keeper repeated his heroics a minute into the second half with an excellent reflex save to keep out Gallen's close-range header.
But the keeper had no chance from the resulting corner when the unmarked Danny Shittu powerfully headed in.
Five minutes from time Gallen wrapped up victory for Rangers, racing on to Steve Palmer's clever pass and rolling his finish through the keeper's legs.
A minute from time Mansfield's misery was complete when substitute Andy Thomson scored with his first touch, turning in Richard Langley's cross from the byline