Both Hetmyer and Gurkeerat hit blazing fifties as RCB recovered from a hopelessly placed 20 for three in the third over to reach the 176-run target with four balls to spare.
During their 144-run partnership for the fourth wicket, Hetmyer smashed half a dozen sixes and four boundaries for his 47-ball 75, while Gurkeerat made 65 in 48 deliveries with the help of eight fours and one maximum.
Gurkeerat was contend to play second fiddle to Hetmyer initially, when the Guyanese was dealing in fours and sixes, but opened up later.
This was the first time that RCB had a hundred-plus partnership since 2013 when Kohli and De Villiers were not involved.
RCB were tottering at 20 for three in the third over but Shimron Hetmyer and Gurkeerat Singh Mann had other ideas.
It rained sixes and fours as the duo of Hetmyer and Gurkeerat blunted the opposition attack with their exemplary batting.
Earlier, Captain Kane Williamson remained not out on 70 off 43 balls as he smashed four sixes and five fours to help Sunrisers Hyderabad amass a challenging 175 for seven against Royal Challengers Bangalore.