Cook played another majestic innings to ease England home in Nottingham
England produced a classy all-round display to demolish Sri Lanka by 10 wickets, levelling the one-day series.
After a short rain delay England put Sri Lanka in and reduced them to 20-4, with James Anderson (3-24) impressing.
Kumar Sangakkara struck a battling 75 before being last man out as Sri Lanka were dismissed for 174 in 43.4 overs.
Captain Alastair Cook hit a wonderful unbeaten 95 and Craig Kieswetter 72 as England - who were delayed briefly by rain - cantered home after 23.5 overs.
It was a performance of staggering dominance from Cook's England, who had been thoroughly outplayed in the previous two matches having won the opener. Wednesday's result means the series - tied at 2-2 - will be decided at Old Trafford on Saturday.
England made the most of the seamer-friendly conditions and, having skittled Sri Lanka for 174, Cook and Kieswetter simply blew the tourists away.
Cook batted like a man possessed, taking 12 off the first over from Nuwan Kulasekara and playing some majestic drives through the off-side as he comfortably outscored the more naturally aggressive Kieswetter.
Another brief rain delay meant England needed a reduced 171 from 48 overs and it was never in doubt, Cook mercilessly feasting on any width as the Sri Lanka attack toiled in vain.
TEST MATCH SPECIAL ANALYSIS
“England have absolutely thrashed Sri Lanka, that is a truly colossal win - they had almost half their overs left. If Cook hasn't answered his critics by now, he might as well give up”
BBC cricket correspondent Jonathan Agnew
Cook brought up his fifty from only 37 balls in the 11th over and Kieswetter, who had fortuitously garnered two boundaries from thick edges, went to his half-century eight overs later, magnificently smearing Suraj Randiv into the crowd over mid-wicket for six.
The difference between the sides in such seamer-friendly conditions was stark and England cruised to victory in the 24th over when Kieswetter clubbed Kulasekara for six and then stole the match-winning single.
At the toss, under gloomy Nottingham skies, Cook had had no hesitation in bowling first, and England soon made Sri Lanka captain Tillakaratne Dilshan's comments that he would have batted seem a touch bizarre.
Anderson swung the ball beautifully, seducing a nick behind from Dilshan in the first over and then, after Tim Bresnan had Mahela Jayawardene caught at slip for nine, Anderson trapped Dinesh Chandimal lbw and had Thilina Kandamby snaffled in the slips.
At 20-4, Sri Lanka's hopes of getting anywhere near a respectable total depended much on the venerable Sangakkara and he was surprisingly joined by Randiv, batting up the order at six.
He helped Sangakkara put on 37, clubbing Stuart Broad over cover with one wonderfully aggressive stroke before being gloved down the legside by the same bowler.
Sangakkara was toughing it out in difficult conditions and Angelo Mathews brought him more fine support play with a stand of 72 in 15 overs, the all-rounder producing the shot of the series so far with a picture-perfect lofted straight drive for six off Jade Dernbach.
Bresnan took revenge for his team-mate with a stunning caught and bowled to get rid of Mathews for 39, before Sangakkara nicked Bresnan past Kieswetter for four to bring up his 64th ODI fifty.
It was Dernbach who came back well to wrap the innings up as he accounted for Kulasekara and Lasith Malinga in the same over, before Sangakkara lofted him to Eoin Morgan at point to be last out for 75.
No sooner had England's reply begun than it was immediately obvious Sri Lanka's total was nowhere near enough.
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