Ten-man Rangers re-established their five-point lead at the top of the Ladbrokes Championship after grinding out a 2-0 win over Morton at Cappielow.
Kenny Miller's 12th goal of the season and a second-half strike from Barrie McKay was enough to see off the determined Greenock outfit after a lacklustre display.
Mark Warburton's men were forced to play the last 20 minutes a man light after Andy Halliday was given a controversial second booking during the celebrations for McKay's goal.
The Light Blues were under pressure to win after title rivals Hibernian trimmed back their lead with victory over St Mirren, but they now march into a duel with third-placed Falkirk in confident mood.
Rangers brought Gedion Zelalem back in to start in central midfield in place of Jason Holt - rested due to a minor knee injury - while the hosts had to do without on-loan Ibrox defender Luca Gasparotto as they faced his parent club.
The opening stages saw Jim Duffy's well-organised Ton troops do well to frustrate their guests, who lacked the fluent look that had seen them score 19 goals in their four previous fixtures.
They did come close with a Miller header from James Tavernier's cross nine minutes in but for the most part, their early attempts broke down on the back of some sloppy build-up work.
Even when Gers did grab the opener 26 minutes in, it was a scrappy affair as Halliday drove a 25-yard effort against Thomas O'Ware.
The ball span up nicely for Miller, who held off Lee Kilday before prodding past helpless keeper Derek Gaston.
Morton were not pinned down into their defensive shape though and had Rangers worriedly turning on their heels a couple of times.
They even had a strong penalty appeal dismissed by referee Barry Cook seven minutes before half-time when Rob Kiernan appeared to handle the ball inside his own six-yard box as he slipped while stretching to intercept a McManus cross.
On-loan Fleetwood striker McManus looked the hosts' best hope of a leveller and came close five minutes after the restart as he fizzed a low drive just wide of Wes Foderingham's right-hand post, although he failed to beat the exposed keeper when Bobby Barr did well to tee him up soon after.
Rangers, who saw Miller shoot wide after being sent clean through by Dean Shiels, were starting to show the same nervous look they bore when dropping points away to Hibs, Livingston and Falkirk recently.
McKay almost relieved the tension as he cracked the Morton crossbar from distance.
But the 20-year-old showed no lack of confidence though as he played a delightful one-two with Miller to find himself through on Gaston, slotting away a fine finish to double his team's lead after 70 minutes.
But Rangers' celebrations were cut short before the game had even restarted.
Halliday - booked just four minutes earlier for tugging down McManus - then looked astonished as he was handed a second yellow after an apparent gesture at the home support spotted by linesman David McKniff.
It was a setback for Warburton but his players gritted their teeth and could have netted again as Harry Forrester and Waghorn both came close late on.