LONDON (AFP) - Jason Roy fell five runs short of setting a new batting record but his superb 162 still helped England win the fourth ODI against Sri Lanka and take an unassailable 2-0 series lead on Wednesday.

Surrey's South African-born opener took centre stage on his home county ground and hammered the second highest individual one-day score by an England batsman.

His fireworks lit up the gloomy, rain-filled South London skies to ensure England captured the series at The Oval. His second hundred in three ODI games, 162 runs off 118 including 13 fours and three sixes, helped England clinch a six wicket win with overs to spare as they chased down their revised victory target of 308 with ease.

And they clinched the series 2-0 with just one game left in Cardiff on Saturday. It was England's second highest successful one-day run chase - and they did it in 42 overs.

Sadly for Roy he fell just five runs short of overtaking the highest score by an England batsman with Robin Smith's 167 not out against Australia at Edgbaston in 1993 still holding firm.

He was bowled by Nuwan Pradeep with England in sight of the finishing line. Jonny Bairstow and Jos Buttler saw them home with 11 balls remaining.

He was helped mainly by Joe Root, whose 65 showed a return to form for the Yorkshireman who had struggled recently and had gone six games with just one score over 11.

But if Root had his mojo back, Roy merely continued in the kind of vain which has made him one of the world's most destructive and stylish one-day performers.

Earlier, Sri Lanka had produced their best batting display of the series so far with four men hitting half centuries. The tourists recovered from losing opener Kusal Perera in the second over, run out by Jonny Bairstow for just a single, to give England's attack the run around.

Eoin Morgan chose to field first and he may have been regretting it for a while as Gunathilake and Kusal Mendis put on 128 for the second wicket off just 111 balls. Mendis was struck 13 boundaries in his 77 while Gunathilaka was also aggressive with seven fours in his 62.

England fought back with Adil Rashid claiming the wickets of Mendis (77) and Gunathilaka (62) but still had to deal with the in-form Danushka Chandimal (63) and his captain Angelo Matthews (67 not out) who picked up the gauntletand helped Sri Lanka amass 305-5 from 42 overs.

England's target was revised up by just three runs but with Roy building up a full head of steam they cruised home comfortably.