Man of the match Bell told ESPN: "A lot of things have changed with different personnel brought in in the last day. It has given the club a massive lift and you can tell by the last few performances that we've turned the corner.
"Everyone talked about Robbie Keane but we were confident to get something out of the game. Obviously we're at home. But it was a wee bit of a surprise to get a clean sheet and a 1-0 result really."
The result left Celtic 10 points behind Rangers, but now having played the same number of games, while also giving their opponents' survival hopes a massive shot in the arm.
Match-winner Maguire added: "Delighted to get a chance to start playing again. Lucky enough the gaffer gave me a start and hopefully I repaid him with the goal."
Killie boss Jimmy Calderwood was thrilled to have inflicted a first defeat on Celtic in 32 meetings between the pair.
He told ESPN: "It's fabulous. They've had a hard time of it this season. It was a wonderful game tonight with the right result.
"Celtic started really well. Robbie was running the show and you got the feeling the script was written for them.
"But we hung on and we started to play a wee bit, started causing them a few problems.
"It gets us up there and nearer to a few other teams - it's great for the club.
"They're a good team, so many attack-minded players. If you let them play you're going to get punished. (The players) have got to take a lot of credit, because the character they showed was great."
Of Maguire in particular, he added: "He's a great lad, he loves playing the game, loves training. The times he was at my door moaning at Aberdeen. to score the winner is wonderful for him."
Celtic manager Tony Mowbray was pleased with what he saw of new boy Keane.
"He gives us a different dimension," he told ESPN. "He's a high-quality footballer. You saw that tonight in flashes. He'll be better for the game, I'm sure, and getting to know his new team-mates.
"We're trying to put a team together that can be successful long term. There were flashes tonight but it didn't run for us."
Mowbray was making no excuses for his side's lack of cutting edge up front.
"There's no excuse," he said. "For a lot of the game we were in the ascendancy. We had enough of the ball, got into decent areas and we didn't manage to score. Goals change games and we didn't manage to score them."
He has not given up completely on catching Rangers but, after passing up the chance to cut the gap to seven points, admitted his team need to start making inroads soon.
"We've got to play Rangers twice, they're games we've obviously got to win," he said. "But it's obviously going to be difficult for us. We've got to start winning very, very quickly."