De Villiers slammed 22-ball 55* to take RCB over the line with two balls to spare.
"In my eyes he's the most impactful player in the IPL," Kohli said at the post-match presentation ceremony.
Chasing 178 to win, RCB lost Aaron Finch (14) early. The duo of Devdutt Padikkal (35 off 37 balls) and captain Virat Kohli (43 off 32 balls) added 79 runs for the second but they failed to keep the required run-rate under check.
After their dismissal, all the hopes were on the shoulders of De Villiers and the South African batting genius once again delivered for RCB. He wreaked havoc on the RR bowlers from the outset to bring RCB back in the contest.
Needing 35 runs from the last two overs, De Villiers smashed three sixes and accumulated 25 runs alongside Gurkeerat Singh Mann (19* off 17 balls) in the 19th over off Jaydev Unadkat.
In the last over, RCB needed 10 and De Villiers whacked Jofra Archer for a maximum to take his team over the line with two balls to spare.
"To be honest, you're always tense in a chase because you're not sure how many balls AB is going to get. Credit to Gurkeerat as well got that important boundary," the RCB captain said.
"It doesn't matter who the bowler is, he does what he does. AB has always been someone who's been ready to look at the situation and adapt his game accordingly," Kohli further added.
"If he goes, the opposition know they have a slim chance and there's a good reason for that. It's purely because of the presence of someone like him that teams feel we are never out of the team," he concluded.
It was RCB’s 6th win from 9 games in the ongoing IPL and they will take on Kolkata Knight Riders in their next clash on October 21.