Virat Kohli hit 67 to guide his Royal Challengers side to their first win of the year's IPL after record-equaling six straight defeats.
Chris Gayle smashed an unbeaten 99 to take Kings XI Punjab to 173-4 after they were asked to bat first, putting extra pressure on RCB.
But the India skipper plundered early runs to put Bangalore on course. Even after the run rate eased, South African veteran AB de Villiers (59*) and Australian Marcus Stoinis (28*) reached the target in the final over to provide a morale-boosting eight-wicket win.
"It is a great feeling to get across the line," said Kohli, who has criticised his players for their mistakes and attitude in past defeats.
"We have been unlucky in a couple of games," he added. "But after so many setbacks the players showed they still have desire."
Kohli's innings included eight fours, but he said the key to the victory was his bowlers taking four Punjab wickets in the middle of their innings to restrict their score.
Only Gayle's concentration -- and his five sixes and 10 fours -- ensured Punjab put up a competitive score.
After Rajasthan Royals beat Mumbai Indians by four wickets earlier Saturday for their second win of the season, Bangalore, who have never won an IPL title, remain rooted to the bottom of the table and needing a miracle to qualify for the playoffs.