Cripps and fellow midfielder Sam Walsh starred in the Blues' thrilling 12.16 (88) to 12.12 (84) victory at the MCG on Friday night.
Cripps had 30 disposals and eight clearances, Walsh had 30 and seven, and young gun Jagga Smith (27 and six) also shone, while Will Hayward kicked three goals.
It was the Blues' third win from as many games with Fraser at the helm after former coach Michael Voss was sacked this month, improving their season record to 4-8.
Cripps stood tall in the dying stages, soaring above Jeremy Cameron to mark close to goal and put Carlton in front for the final time with 70 seconds left to play.
"Sometimes you pop up in those moments and just take them," Cripps told broadcaster Kayo Sports post-match.
"Not going to lie, it was a pretty out-of-body experience after I kicked that, but there was still another minute to go (and) we were able to ice the game."
Geelong (8-4) could slip out of the top four by the end of the round despite the efforts of Bailey Smith (35 disposals), Max Holmes (25 touches) and spearhead Cameron (four goals).
In a tight contest, the Cats were controversially denied the opening goal when Ollie Dempsey shinned one through on the line and a behind was called.
The ball was brought quickly back into play before the decision could be overturned on video replay.
"We were denied a goal but mistakes happen," Cats coach Chris Scott said.
"There should have been a review called and they (the AFL) will work through those processes.
"But that's one minute into the game and then the rest of the game didn't work out the way we would've liked."
Dempsey left no doubt later in the first quarter when he nailed a superb snap under pressure on the outside of his right boot.
It was the Cats' fourth consecutive goal in the opening term, giving them a 19-point lead at quarter-time.
But the second quarter was all Carlton, who gradually made their territorial dominance count on the scoreboard as they cut the margin back to five points by the main break.
Flynn Young kicked two goals in the second term and was only denied a third by a finger when replays showed his snap-shot was touched off the boot.
Carlton hit the front at the two-minute mark of the third quarter when George Hewett was taken high by Smith and converted his free kick.
It was the first of three lead changes for the term and the teams went goal for goal in the final quarter until Jack Henry gave the Cats the lead with a quick snap at a stoppage with less than three minutes to play.
But the Blues had a little left in the tank and reclaimed the lead when Cripps stepped up.
"(Geelong) are an incredible team and they had momentum at different stages, and I thought we were able to manage that throughout the game reasonably well," Fraser said.
"I think that's a part of our game that's grown.
"But to be able to have some composure and stay well connected and execute for the large part the way we wanted to and come away with the result should keep building belief for the players."
