India captain Shreyas Iyer said his T20 world champions were in "transition" after another heavy defeat saw England complete a series-clinching success in Bristol on Thursday.
England captain Harry Brook smashed an unbeaten 79 from 35 balls and Phil Salt finished on 59 not out as the hosts overhauled India's modest 158-7 with more than six overs to spare.
Brook struck eight fours and four sixes while Salt's innings contained nine fours and a six.
Victory came just two days after England inflicted India's heaviest T20 defeat in terms of runs – a 125-run thrashing at Trent Bridge – and left them 3-0 up in the series with just Saturday's finale at Southampton remaining.
"It is always good to beat India as they are a strong side and have been for many years," said Brook.
England fast bowlers Jofra Archer and Josh Tongue backing up impressive displays in Nottingham with two wickets each.
Iyer provided rare resistance with an unbeaten 80 from 49 balls.
But India still suffered a record fifth straight T20 defeat following their shock 2-0 series loss away to Ireland.
Brook and Salt, bowled from a free hit on four, ran riot against an attack without spinner Varun Chakravarthy and seamer Harshit Rana, both of whom suffered series-ending hamstring injuries in Nottingham.
India came on tour without rested star fast bowler Jasprit Bumrah and injured allrounder Hardik Pandya.
"It was a disappointing one, 158 wasn't a perfect total on the board and eventually we saw how quickly they (England) chased it down," said Iyer.
"I think we were a bit short on our execution. When we tried change of pace or something else they got boundaries.
"This is a transition phase and we will be making a lot of mistakes. A lot of youngsters were playing in these conditions for the first time."
'COOL TO BE NO. 1'
England will go top of the T20 world rankings if they win at Southampton,
"It would be pretty cool for us to be world No 1, to be honest. That is definitely an aim," said Brook.
India, who won the toss, at least improved upon their woeful 76 all out in Nottingham.
Teenage opener Vaibhav Sooryavanshi struck Tongue to the cover boundary and hit an upper cut for six, but the 15-year-old rising star was again unable to better his age after scores of 13 and 14.
Sooryavanshi fell for 15 when he skied Archer to mid-on, falling to his Rajasthan Royals teammate just as he had done at Trent Bridge. And India were 48-3 when legspinner Adil Rashid ran 20 yards to catch Abhishek Sharma.
Iyer and Shivam Dube repaired the innings, albeit in sedate fashion.
The fourth-wicket partnership was worth 53 from 43 balls when Dube holed out in the deep to offspinner Will Jack's slower ball.
Iyer reached his second fifty of the series with a six off Rashid.
Arshdeep Singh had Jos Buttler caught behind, but it was one-way traffic from then on as Salt and Brook shared a stand of 146.