After taking an unbeatable 3-0 lead following a thumping nine-wicket victory in the last match, world champions India struggled to adapt to the conditions and allowed England to score more than 230 runs for the first time in the series.
Root's well-judged 113 from 108 balls, his highest ODI score, lifted England to 294 for seven off their 50 overs. Captain Alastair Cook chipped in with 46 and Jos Buttler fell for a breezy 49 after being run out by Mahendra Singh Dhoni.
Man-of-the-match Root, who smashed 10 fours and three sixes, put on 108 runs with Buttler before Dhoni knocked off the bails to break the fifth-wicket partnership after Buttler set off for a non-existent run.
Mohammed Shami ended Root's entertaining innings in the 46th over when the right-hander flicked the ball straight to Ravichandran Ashwin.
India's hopes of completing a 4-0 rout got off to a rocky start when they lost Edgbaston centurion Ajinkya Rahane for a duck after he nonchalantly sliced a James Anderson delivery into the hands of Eoin Morgan in the first over.
From then on the visitors struggled to build momentum and they lost wickets at regular intervals, leaving Ravindra Jadeja frustrated as his swashbuckling knock of 87 off 68 balls turned out to be in vain.
The left-hander was last man out, clean bowled by Steven Finn in the penultimate over as he tried to score runs quickly in a bid to reach three figures in an international for the first time.
Despite the defeat, India will be buoyed by their 50-overs performances in England as they look to fine-tune their game before beginning the defence of their World Cup title in February.
England, however, face an uphill task if they are to get their hands on the 50-overs World Cup, a trophy they have never won.
They have won only one series against another test-playing nation since 2012 and have lost their last four at home.
Their consolation victory has done little to paper over the cracks that run deep in England's approach to the limited-overs format which some former players have labelled as old-fashioned and out of date.
- Sports & Recreation
- Mahendra Singh Dhoni
- Jos Buttler