Ashwin (33), however, tried to pace up the innings but in the process the off-spinner also got out in the penultimate over.
As enchanting as De Villiers' innings was, Umesh Yadav's superlative effort with the ball (3/23) was equally crucial, if not more, in RCB's win. The 17th over bowled by Mujeeb Ur Rahman turned out to the game changer as de Villiers hit two consecutive sixes out of 19 runs from that over.
Rajasthan's batting was not particularly impressive either that night or in the game before; D'Arcy Short and Ben Stokes are yet to fire, and RCB will be wary of their abilities.
Having finished rock-bottom in 2017, RCB's new campaign started with a defeat at Kolkata Knight Riders, but two of their star-studded top four fired on Friday as the visitors' 155 all out was overhauled with three balls to spare.
De Villiers (57 off 40 balls) played anchor after the early departure of captain Virat Kohli (21), before he made a decision to take on the bowlers towards the end for some lusty blows. "The general message shared by the team is to stay busy and take the game to the next level always", de Villiers told RCB according to a press release.
Then the responsibility was performed well by AB de Villiers (57) and Mandeep Singh (22) till both got out in the 19th over providing some twist to the match. After two dots, Yuvraj Singh swatted the fifth ball to the boundary but Yadav had the last laugh by ripping one through the left-hander's gate. Brendon McCullum got out for a duck in his last outing and if all four manage to click then it could mean curtains for RR. In the next over, de Villiers deposited Mohit Sharma into upper tier and with that, he brought up his fifty. The move paid rich dividends as Yadav ran through KXIP's top order, prising out Mayank Agarwal, Aaron Finch and Yuvraj Singh in the fourth over, before finishing with 3 for 23.
Earlier, Kings XI Punjab were bowled out for 155.
Rahul found an able partner in Karun Nair and the duo put on a 58-run stand to steady the Punjab ship.
Rahul and Mayank, the KXIP openers, who are no strangers to this ground, showed a lot of promise, the former even hit Chris Woakes for 16 runs in the first over. At the end of 15th over, KXIP were 122 for 7 and they could add 33 more runs at the expense of three wickets thanks to Ashwin's breezy 21-ball 33. In his 30-ball knock, he slammed two boundaries and four sixes.
After Rashid Khan, young Afghanistan spinner Mujeeb ur Rahman has been touted as the next big thing to arrive from the Afghan country, after his impressive performance in the last two matches for the Punjab-based franchise.