The Hoops assistant manager was promoted on Wednesday morning following the resignation of Neil Lennon and got off to a winning start thanks to in-form striker Odsonne Edouard.
The French forward scored his 21st goal of the season with a deflected strike in the eighth minute of a first half mostly dominated by the home side and, while Aberdeen improved after the break, they could not fashion a leveller.
It was not markedly superior fare than that served up under Lennon but the managerless home side moved 15 points behind Old Firm rivals Rangers at the top of the Scottish Premiership having played a game more and, while hopes of a 10th successive title have long been in ruins, Kennedy can do no more than keep winning.
There was intrigue around his first team selection and in the event he made two changes, one enforced.
Defender Diego Laxalt came in for injured Greg Taylor and Polish striker Patryk Klimala replaced Tom Rogic for his first start since the defeat by Rangers in October, while for the Dons, former Celtic winger Jonny Hayes replaced injured striker Fraser Hornby.
The Granite City men were first to threaten.
Defender Ash Taylor hit the bar in the fifth minute with a looping header from a Niall McGinn corner then seconds later forced a fine save from Celtic keeper Scott Bain with a close-range header from another corner.
However, moments later, the home side through their prolific striker and with some good fortune.
With time and space, Edouard took a pass from Ryan Christie at the edge of the Aberdeen box and fired in a shot which took a deflection off defender Tommie Hoban and wrong-footed keeper Joe Lewis, for his ninth goal in nine games.
The Parkhead side should have doubled their lead in the 20th minute when right-back Jonjoe Kenny's inch-perfect cross from the right found Klimala but he somehow managed to direct it past the post from six yards.
Celtic dominated the ball up until the interval with Aberdeen starting the second half with more purpose and another threat from a corner where Klimala headed away another header from Taylor.
The home side kept probing but as the game unfolded further neither keeper was seeing much action.
The Dons defence was equally focused, although Hoops midfielder Callum McGregor came close with a drive in the last minute before Edouard passed up a good chance in a late counter-attack.