While a flat and dejected crowd may have been anticipated after the weekend's Old Firm loss that all but confirmed Celtic as champions, more professionalism was expected from the Rangers players.
Instead, the home crowd were left frustrated in the first half, witnessing petulant play from Fabio Silva and Cantwell and uncertain defending.
There were flashes of decent stuff from the hosts. Ridvan Yilmaz had one saved by Jon McCracken, Mohamed Diamonde saw one whistle wide and McCausland had a shot saved when one-on-one.
Despite that, the crowd was quiet and then silenced when Dundee went ahead, as Owen Dodgson’s low ball was buried at the back post by McGhee.
There was barely enough time for any boos before the visitors extended their lead. Dodgson was the provider again, crossing low for Portales to flick the ball into the bottom corner.
Rangers managed to sober up quickly, with McCausland squeezing into the box and poking through McCracken’s legs to ease the tension at half-time.
The jeers were deafening at the break, but Rangers responded well. Cantwell, who looked a different player in the second half, curled a delightful cross in and Dessers powered a header into the ground which bounced into the top corner.
Cantwell completed the comeback himself, lashing a cross over McCracken and sneaking it in at the back post. His badge-kissing celebration suggested he meant it.
Rangers piled on the pressure, with Dundee’s confidence diminishing quickly. Eventually, Wright wrapped up the victory when Kieran Dowell picked up a loose ball and crossed to the back post, with the substitute passing it into the net.
It would be more than comfortable in the end. The visitors had wilted and left themselves open, allowing McCausland to find Wright on the left, with the former Dundee winger skipping inside to score his second and Rangers' fifth.