A touch player in an England top-order replete with power-hitters, Root's unbeaten 133 was a characteristically majestic innings by a batsman almost incapable of playing an ugly shot.
England's number three battled cramp to anchor a tricky 300-plus run chase, constructing his 129-ball knock in a meticulous manner and staying at the crease for almost 45 overs to score the winning runs with back-to-back boundaries.
The 26-year-old England test captain paced his innings to perfection, using 59 balls for his first 50 runs, three fewer for his second and accelerating to score his final 33 off just 14 deliveries.
"Whatever you throw at Joe Root, he proves that he can do it," former England captain Alec Stewart said on the BBC's Test Match Special. "He has mastered test cricket, 50-over and Twenty20 cricket. Whenever England need him he scores runs.
"He plays safe shots and scores at a run a ball. That is all you can ask."
Root did hit one six, depositing a Rubel Hossain delivery into the stands, but only after he had brought up his 10th one-day century and wanted to control the asking rate.
His calming presence allows the big-hitters around him a freedom to play their natural game and Alex Hales demonstrated the tactic impeccably by smashing a belligerent 95 in his 159-run partnership with the Yorkshireman.
Root later combined with skipper Eoin Morgan to secure the comprehensive eight-wicket victory with 16 balls to spare, giving England a perfect start to their bid to win a first global 50-overs trophy.
"Joe is the glue in our side," Morgan, who made a quickfire unbeaten 75, said after England's triumph at the Oval.
"He really has scored a lot of runs in the last couple of years and continues to do it."
Morgan also dismissed suggestions that Root, whose career-high ODI score earned him the man-of-the-match award, was either too tardy for the format or incapable of big-hitting.
"It's not slow, it's actually at pace," Morgan said.
"He has been working on his power hitting and today it paid off. He hit a few into the stands which was outstanding."
England next play New Zealand in Cardiff on Tuesday.
(Reporting by Amlan Chakraborty in New Delhi; Editing by John O'Brien)
