Root's maiden ton steers England to 303-6
English batsmen Joe Root celebrates scoring a century during the third and last One Day International match between West Indies and England at the Sir Vivian Richard Stadium in St John's, March 5, 2014 - by Emmanuel Dunand
On a pitch with much more even pace and bounce than for the first two fixtures, Root battled through the considerable pain of a badly bruised right thumb -- inflicted at the start of his innings by Ravi Rampaul -- and reached the landmark in the 45th over off 112 balls with seven fours.
Buttler's effort also merited a three-figure total as the wicketkeeper batsman led the assault on the West Indies bowlers in a 175-run fifth-wicket partnership, striking seven fours and four sixes off 84 deliveries.
But he missed out on a century when he was caught-and-bowled by Rampaul for 99 seeking the single to take him to three figures in the final over of the innings.
Home captain Dwayne Bravo was left to regret his decision to field first on winning his first toss of the series as even top spinner, Sunil Narine was collared by the fifth-wicket pair as they combined to smash 21 runs off his ninth over.
Narine had claimed the important wicket of the experienced Eoin Morgan at the start of his spell to have England 116 for four in the 24th over.
Opening batsman Moeen Ali was the star performer in the first half of the tourists' innings stroking 55, his maiden half-century, before falling caught-and-bowled to left-arm spinner Nikita Miller.
But Root and Buttler grew in confidence the longer their partnership progressed with the West Indies further handicapped by the inability of Marlon Samuels, back in the side but clearly still hampered by a groin strain, to get beyond the fifth over of his expected ten-over spell.
Bravo eventually broke the partnership in the penultimate over, having Root caught at short third-man attempting a reverse sweep.