The Gers went into Sunday’s game on the back on their Europa League triumph against Jose Mourinho’s Fenerbahce during the week.
Powered by goals from Nico Raskin, Mohamed Diomande, and Hamza Igamane, Rangers secured their first win at Parkhead in five years.
“It is a brilliant feeling, I am delighted for the players, everyone involved on the staff and most importantly the 2,500 supporters who were here," he told the club website.
“Hopefully we have sent them home happy and the hundreds of thousands watching on TV.
“I have to give them huge credit, their application was what I want from a football team, mixed in with good football.
“After Thursday and what they put themselves through to produce a performance like that, especially in the first half, I am proud of them.
“We came with a game plan and we thought we could hurt Celtic and we did that. We knew they would have chances and that’s when you need your goalkeeper and defenders to do their jobs.”