West Indies opener King produced a superb knock which included eight fours and five sixes as the hosts recovered from a perilous 54-4 to finish on 176-7 at the National Stadium in St. George's.
Powell, meanwhile, also caught the eye with a swashbuckling cameo at the crease that helped give West Indies a fighting chance after England won the toss and opted to bowl.
The West Indies captain's half century came off just 28 balls and included five sixes and three fours.
The highlight of Powell's knock came in the 16th over, with Powell mauling England bowler Sam Curran for 30 runs.
After sending the first ball of the over for four, Powell crushed back-to-back sixes off the next two deliveries.
After a fourth ball wide, Powell bludgeoned two more sixes high into the stands.
A wild over finally ended with Curran dismissing Powell as he went for another six down the ground, only to be caught in the deep via a brilliant diving catch by Harry Brook.
Adil Rashid was the pick of the England bowlers with figures of 2-11 off four overs.
West Indies lead the five-match series 1-0 after beating England by four wickets in the opening T20 in Barbados on Tuesday.
Brief scores:
West Indies 176-7 in 20 overs (B. King 82 not out, R. Powell 50, K. Mayers 17; A. Rashid 2-11, T. Mills 2-30)
Match situation: England need 177 to win
Toss: England
