India started and spluttered to 233 all out before Root continued his superlative form to get the Three Lions over the finish line with 35 balls to spare.
But it wasn't straighforward for England. In the chase, the hosts found themselves 53/3. Ben Duckett got a first-baller from the mercurial Jasprit Bumrah, then Jacon Bethel couldn't deal with a short ball and England were 8/2 in the fourth over.
Captain Harry Brook tried too hard. He lost his bat in an ill-attempted slog, got clocked twice in the midriff trying to pull deliveries that weren't short enough then smashed on the helmet during a poorly executed ramp effort. India's Gurnoor Brar then drew an inside edge after Brook tried another ramp shot. He departed for 16.
But never fear, Root is here. The veteran racked up his fifth consecutive half-century and would finish one shy of a deserved century from 133 balls. His composure, combined with Sam Curran's 26 and Will Jacks' 30 sealed the victory.
Earlier, India had a steady start. Shubman Gill (31) was first to fall in the eighth, then Jacks brought a merciful end to Rohit Sharma's curious 26 from 47.
Virat Kohli meant business. The legend racked up his 78th score of 50 or more and put a run-a-ball 67 partnership with Shreyas Iyer (66).
But Jofra Archer returned for a match-winning spell in the latter overs, dismissing Kohli (65) as well Axar Patel (1) and Shivam Dube in consecutive deliveries to finish with 3/47. Gus Atkinson also chipped in with 3/50 to bring India's innings to a premature end.
France coach Didier Deschamps has urged his players to end their FIFA World Cup campaign on a positive note by beating England in Saturday's third-place playoff, even though neither side wanted to be playing for the bronze medal.
Anthony Gordon admitted England's heartbreaking World Cup semi-final defeat to Argentina will stay with him for some time, saying he believed the Three Lions were finally destined to end their decades-long wait for glory.
Alexis Mac Allister believes Argentina's 2-1 World Cup semi-final victory over England reinforced the idea that technical football continues to thrive despite the sport's increasingly physical demands.
Harry Kane has refused to rule out playing at another FIFA World Cup after England's latest bid for major tournament success ended in painful fashion with a 2-1 semi-final defeat to Argentina.
