A goal in the second minute from Steven Davis, his first of the season, put the Light Blues on their way before Nacho Novo popped up in the 86th to secure a vital win.
With Celtic losing 2-1 to Hibs at Parkhead this was a big night for Walter Smith’s men who had to show plenty of commitment to get the victory they desperately wanted.
Despite suffering an early blow Gus MacPherson’s men fought back and in the second half had the majority of possession and goalscoring chances.
This Rangers squad, however, has plenty of resilience and it was again evident on this trip to New St. Mirren Park.
They were handed a pre-match boost with the news that Nacho Novo and Kenny Miller were back in the starting line-up.
The attacking duo were missing on Saturday due to injury but added an injection of pace to the Gers team.
The gaffer also showed faith in Kyle Lafferty, who partnered Miller up top, and the striker played a key role in his side’s quickfire opening goal.
Davis beat the Saint’s offside trap to latch on to his countryman’s long pass and the midfielder had time and space to prod a low shot past Paul Gallagher.
To be fair to the home side they responded well and a Billy Mehmet header from a Jack Ross cross had to be watched closely by Allan McGregor.
David Barron then tried his luck from distance but his driven effort was well wide of target.
Rangers, however, quickly got back in to the game and they had plenty of opportunities to double their advantage before the half hour mark.
On 13 minutes Lafferty cut inside from the left wing and having darted past two defenders his curling shot from 20 yards was well saved by Gallagher.
Moments later the ball was back in the Saints’ 18 yard box and when it fell to Lee McCulloch his shot on the turn clattered the underside of the cross bar before being cleared.
With 21 minutes on the clock Miller showed his quality when he skinned John Potter down the left flank and his cross was chested out nervously by Jack Ross who had slipped.
It came out to Davis and his left foot shot across goal was palmed away by the busy Saints keeper.
It was proving to be an entertaining contest between two committed sides but Lafferty, who had worked his socks off in the early stages, showed a bit too much aggression in a challenge on Potter and was booked as a result by Craig Thomson.
A bit of handbags followed but Walter Smith and Ally McCoist voiced their frustration to the fourth official when Michael Higdon was let off the hook for a similar challenge on David Weir.
There was now an edge to the game with St. Mirren pushing forward and Rangers looking dangerous on the counter attack.
On 41 minutes the energetic Davis again darted forward menacingly and he found Lafferty in space on the left.
He decided to shoot first-time but Potter threw himself across the turf to stop his netbound effort.
Before the half was finished the referee did book a Saints player and he didn’t have any option this time.
With the ball bobbling about midway in to the Gers’ half McCulloch latched on to it but was caught late on the shin by a poor challenge from Steven Thomson.
A yellow card was issued as a result and the half-time whistle perhaps came at a good time with this encounter now simmering.
But despite a 15 minute break both teams came out for the restart with renewed hunger.
On 48 minutes a powerful left foot snap shot from Steven Whittaker almost broke an advertising board behind Gallagher’s goal and at the other end Garry Brady found himself in a great position but his poor shot rippled the side netting.
It was end-to-end stuff and with the Saints pushing forward Novo found Lafferty down the right channel.
He had Kenny Miller in space at the back post but decided to go alone and his powerful right-foot thunderbolt was punched away by Gallagher at his near post.
On 60 minutes Walter Smith made his first change with Kevin Thomson going on for Lafferty and Novo joining Miller in attack.
But in the very next passage of play the home side should have been on level terms.
Brady delivered a superb cross and from eight yards out and unmarked Mehmet glanced a header wide.
With 65 minutes gone Novo was also guilty of missing a snip.
Thomson swung a deep cross in, again from the left, but Nacho’s downward header bounced off the surface before going inches past Gallagher’s left hand post.
With Rangers unable to bag a second at this stage St. Mirren remained a threat and with 15 minutes to go Steven Naismith was given his first run-out in over a month in place of the impressive Miller.
But having played well in the first-half the second was proving far from comfortable for the Light Blues who struggled to impose themselves on the game after the interval.
Fortunately, however, the rock solid partnership of Weir and Danny Wilson held strong and on 86 minutes Novo landed a classic sucker punch blow.
Davis curled a pass down the right wing and when David Barron misjudged his header it let the Spaniard sprint clear.
Despite being at a tight angle the no. 10 smashed the ball past Gallagher at his near post with typical aplomb, sending the traveling support in to ecstasy in the process.
As Walter Smith predicted in his pre-match interviews this was a tricky test for his team to overcome but they got the win they were after and at this stage of the season that’s all that matters.