The young Gers fought from behind to secure victory in the game, with Kemar Roofe getting the scoring underway after playing the opening 45 minutes in his return from injury.
Indeed, the 31-year-old was replaced at the interval by Chris Eadie, 15 years his junior, while there was also a B Team debut for Blaine McClure in midfield.
Speaking to RangersTV after the contest, the Gers B assistant coach commented: “Kemar Roofe started the game and he was great pre-match with the younger ones, being round about them, which is great for everyone.
“The younger ones who went on play with a passion, desire and freeness, which I think we saw in the second half.
“It’s great that we have a wealth of talent at the club. The B Team is obviously there for the first-team manager to utilise players that he wants to see play, and they’re always a joy when they come down.
“They make it easy for myself as a coach with their good habits; the way that they prepare and get themselves ready for the game.
“That’s part of what this B Team is about, for the young ones to learn off the senior pros.”
The Gers would have been disappointed at the manner of the Dundee goals in the first half, trudging in at the interval behind despite Paul Nsio restoring his side’s advantage midway through the opening period.
However, the home side emerged for the second half with a renewed purpose, scoring three times without reply thanks to a brace from James Graham and an Archie Stevens strike.
Thomson added: “First and foremost, we were very slow in our approach; the ball speed wasn’t great.
“Then, of course, we made mistakes to boot which gave us a real mountain to climb at half-time.
“We’re expected to win at Rangers Football Club and to win every game. We know there is always a pressure on us to perform and we made the task even more difficult by going behind.
“It was simple at half-time: we spoke open and honestly to certain individuals, then collectively, about what we had to do together in order to get that win.
“We had a real intent in the second half, although I’m not saying we didn’t in the first half. But in the second half we were backing things up, getting the second and third balls in order to allow us to go and attack.
“A lot of young talent went on in the second half who are keen and eager to want the jersey.”