Chasing 158 for victory, the Daredevils were restricted to 137 for seven by last year's runners-up who were served well by Muralitharan's three for 25, after De Villiers set it up with a blazing 64 off 42 balls.
De Villiers hit six fours and two sixes in an innings that gave Bangalore the platform.
Image: Royal Challengers Bangalore Muttiah Muralitharan, right, and teammate A.B. de Villiers leave the ground as they celebrate their win over Delhi Daredevils in their Indian Premier League (IPL) cricket match in Bangalore, India, Saturday, April 7, 2012. Royal Challengers Bangalore won the match by 20 runs.