The Ibrox men were lucky to return to the Somerset Park dressing rooms at half-time on Saturday not trailing to Ayr United.
Bell made a string of saves - including an outstanding instinct stop to deny Michael Donald after half an hour - to keep the League One leaders in it.
They then stepped up their game after the interval as Nicky Law bundled home the opener within 30 seconds of the restart before Jon Daly nodded home his 21st goal of the season to confirm a 2-0 win.
On this kind of form, Bell may have an outside chance of sneaking into Gordon Strachan's Scotland squad for next month's friendly clash in Poland when the Dark Blues boss names his group on Wednesday.
McCoist - whose side are now potentially five games away from clinching promotion to the Championship - said: "He made some brilliant saves, particularly the one first half was a brilliant save.
"He's doing well and it's another clean sheet and he should be very proud of that.
"That's as good a performance as you'll see from any keeper in the country.
"He's been top class. In history, Rangers goalies have always been called upon to make saves at crucial times when we've had large amounts of possession in the game.
"He did that today and even speaking to (Ayr goalkeeping coach and former Rangers player) Andy Goram after the game he thought he was very good which is praise indeed."
Rangers got off the hook as Bell denied Donald as the ball fell to him from a corner, diving to his left to palm away a powerfully-hit effort.
From the loose ball, Rangers sprang forward but saw Fraser Aird smash the ball off the bar before Law was left with a red face after skying over an empty net.
But the former Motherwell man made up for his sitter by forcing Aird's cross into the net at the start of the second period while Daly beat Ayr keeper David Hutton to Lee Wallace's cross for the second on the hour mark.
The victory came on the same day as headlines appeared on the back pages claiming McCoist believed Rangers would need to spend £30million to mount a challenge to Scottish Premiership champions Celtic upon their return to the top flight.
But the Light Blues boss insisted his words had been twisted, saying: "Not at any time did I say £30 million would be required to get Rangers back to the top.
"I said I think we lost £30 million worth of talent. I am not saying that's what would be needed to take us back to the top."
Ayr boss Mark Roberts admitted his side had switched off by allowing Law to score so soon after half-time.
He said: "We had a game plan which was working great and created a few great chances. When we got in at half-time level, we were in a position where we needed to ensure we went back out and needed to concentrate and not do anything daft.
"But we made a silly mistake straight from taking the centre which allowed Rangers to go straight up the park and score. It's criminal to make a silly mistake like we did when you are playing against the best side in the league.
"Rangers have that quality and as soon as you concede against them their better players come to the fore."