The visitors were stunned by their rivals, who barely settled in either half but enjoyed the support of their 5,000 fans
Nigeria's Leon Balogun and Zambia's Fashion Sakala were missing as Rangers went down 1-0 to Dundee United at Tannadice Park on Saturday.
The home side scored the only goal of the game in the second half through Jamie Robson to stun the Premiership heavyweights as Sakala and Balogun were not included in the matchday squad.
Dundee came close to getting an opener in the fifth minute when Logan Chambers shot low from the edge of the box, but his right-footed effort was collected by Jon McLaughlin.