3 July 2016 04:52 am
Joe Root struck a measured 93 and helped England to 324-7, sharing a 109-run stand with Jos Buttler, who made 70 off 45 balls.
David Willey took 4-34 and Liam Plunkett 3-44 to help Sri Lanka out for 202 with 7.2 overs unused.
Sri Lanka are still without a win against England on this tour, with only Tuesday's Twenty20 remaining.
England move above Sri Lanka to fifth in the International Cricket Council rankings, and look a different side to the one that exited last year's World Cup at the group stages.
James Vince, who struggled in the Test series against the same opposition, did well to make a maiden ODI half-century but threw his wicket away when trying to cut loose off the spin of Danushka Gunathilaka, who took 3-48.
In the run chase, Gunathilaka's 48 proved useful after some early wickets, but after his dismissal to Plunkett only Dinesh Chandimal could provide some resistance with 53 until he was bowled by Willey.
On a pitch that had looked to favour seam bowling, spinner Adil Rashid picked up 2-41 in 10 overs, and Willey returned late on with two 41st-over wickets before sealing victory in his next.(BBC)