There were fireworks and former players, including members of the 1972 European Cup Winners' Cup-winning side, on the Ibrox pitch to mark the occasion, before second-half goals from David Templeton and Andy Little ensured the party was not pooped.
A season-high crowd of 49,913 watched on and McCoist admitted relief his players did not disappoint, saying: "I was a little bit concerned, with the way things were shaping up, that we would end up with a damp squid and the result not going our way. I'm mightily relieved and pleased."
"The occasion was fantastic for everybody involved with the club. It was an opportunity for some great stars and players of the past - and indeed the current players - to celebrate the club's 140 years.
"It was also a chance to say a thank you to those fantastic supporters."
McCoist paid tribute to goalscorer Templeton, who made his first start since suffering ankle ligament damage in mid-September and drew four bookings and a subsequent sending-off from his opponents.
"He lulls defenders into situations where they are going to have to tackle him," McCoist said of the winger.
"It's testament to him after a few hefty slaps that he still wants to take the
ball and commit defenders."