Rangers are just four points from the title as a late Alfredo Morelos winner saw them past battling Livingston.
Manager Steven Gerrard was sent to the stand on a tense night in West Lothian, as his side struggled to find a way through.
His fury was sparked by a booking for Morelos, who spurned several good chances to put his side into the lead.
But El Bufalo came up trumps in the end, turning home at the back post to leave his side on the edge of glory.
They'll take the title this weekend if they beat St Mirren and Celtic fail to take three points against Dundee United on Sunday.
Gerrard made two changes from the win over Antwerp, with Nathan Patterson coming in from the start and Scott Arfield replacing Ianis Hagi.
The hosts were looking to bounce back from their loss to St Johnstone in the League Cup final and David Martindale made four changes to his XI.
Max Stryjek came in for Rangers-owned Robby McCrorie in goal with Craig Sibbald, Gavin Reilly and Jack Fitzwater also in.
Livi started brightly as they looked to push up high and put pressure on the visiting defence, with Reilly hitting an early shot straight at Allan McGregor.
As the half went on though Rangers began to get a grip on proceedings, without ever really testing the Livi defence.
Reilly was forced off after just 21 minutes, with Scott Robinson coming on to replace him.
The substitute soon teed-up Jason Holt for a strike at goal but it was well blocked by Filip Helander.
The Swede nearly made an impact at the other end but he could only head over after getting on the end of a corner.
Morelos thought he should have had a penalty 10 minutes before the break as he went down under Strykej's challenge but John Beaton showed the striker a yellow card for diving.
Rangers were in the ascendancy and Arfield should have opened the scoring only to screw it wide on his left foot.
But it was the Morelos incident that proved the most notable incident of the half.
Gerrard was incensed by the booking for his striker and marched onto the pitch to confront Beaton as the teams headed for the dressing room.
After a booking for swearing at the official the Rangers manager continued to vent and was swiftly shown a second yellow, watching the rest of the match from the stands.
Connor Goldson thought he'd given the visitors the lead shortly after the break but his header was correctly ruled out for offside.
The only fireworks of the first half had come from the Rangers manager, but Beaton was forced to stop play in the second half as pyrotechnics outside caused debris to rain down on the pitch.
The action on the turf was far from explosive though, with neither goalkeeper having much to do.
Morelos should have opened the scoring with 15 minutes to play but he blasted well wide of the far post after picking it up in the box.
He fluffed another glorious chance at the back post after Goldson's flick from a corner and you started to get the impression a goal was never going to come.
But El Bufalo did get his goal late on, turning in after Stryjek had saved from Kent.
The game will not live long in the memory when the story of the title is told, but the champagne will be on ice for Sunday.
3 talking points
Gerrard sees red
The Rangers manager has been projecting a calm and measured demeanour throughout the season but it's clear he wants the title wrapped up as soon as possible.
Gerrard was furious with the decision not to award Morelos a penalty, swearing at referee John Beaton and gesturing furiously.
The Ibrox boss was inevitably sent to the stand but the fact he was so wound up at 0-0 with 45 minutes to play shows how close his team are to glory.
Livi aren't going anywhere
Any notion that David Martindale's bubble had burst after four games without a win were put to bed on Wednesday night.
His Livingston team were dogged, organised and left Rangers looking toothless for long spells.
The pressure told in the end as Morelos grabbed a winner, but Livi have plenty of positives to take.
Not the greatest advert
This isn't the kind of game that would have been a treat for any neutrals viewing on Sky.
There were some things to admire - Livingston's organisation, the excellent Glen Kamara - but a rogue firework display and some Scouse swearing were the highlights.
Livingston battled well, Rangers moved a step closer to the title. Let's never speak of this again.