Nikica Jelavic and Maurice Edu were on target as Rangers profited from two second-half penalties in Inverness.
Jelavic slammed in the first after Ross Tokely had been sent off for sliding in on Steven Naismith.
Following a tumble from Dorin Goian, Jelavic saw his second effort saved but Edu clipped in the rebound.
Rangers also had a man sent off, with Edu picking up two bookings, but the visitors held on comfortably to claim their second win of the season.
Both penalty awards were contentious but the visitors will think justice was done after two earlier handball offences from Terry Butcher's side went unpunished and an early effort was harshly ruled offside.
Rangers striker Jelavic had the ball in the back of the net with just three minutes gone after pouncing on a Edu touch but the American midfielder had been flagged by a linesman.
Inverness were pinned back for long spells in an untidy first half but sprung a promising counter-attack on 22 minutes, only to see Aaron Doran send a weak first-time shot straight at Allan McGregor from 18 yards.
McGregor was busy again when Kyle Bartley was short with a headed back-pass, forcing the keeper to race out and save bravely at the feet of Gregory Tade.
Some nice footwork from Edu allowed the US international to drive to the byline and his cross was headed against the outstretched arm of a defender by Jelavic.
But referee Euan Norris waved away the first of two vociferous penalty claims from the visitors.
Another Inverness breakaway saw Doran flash the ball across goal from the left and a sliding Richie Foran was inches away from connecting at the back post.
With half-time looming, Rangers were again appealing in vain to Norris for a penalty when a double ricochet struck the arms of two defenders as Edu prodded the ball forward.
Both sides were guilty of pumping long, aimless balls up front in the early stages of the second half, with a swirling wind making life difficult for defenders.
Naismith was scurrying after a loose ball near the hour when he was stopped in his tracks by Tokely. And this time Norris pointed to the spot.
The defender, who was shown a red card, appeared to take a large chunk of the ball and the home side's frustration was compounded when Jelavic hammered the penalty kick home.
A second penalty for the visitors was awarded soon after when Goian, running away from goal, tangled ever so slightly with Tom Aldred.
Ryan Esson made a great block from Jelavic's spot-kick but Edu was first to the rebound and tucked the ball away.
Naismith squandered a great chance by toe-poking wide before Rangers were also reduced to 10 men when Edu picked up a second yellow card for a late tackle on Nick Ross.
Steven Davis flashed a shot wide as Rangers pressed and a late Inverness rally was thwarted by good blocking tackles from Ross Perry and Goian.