Although 26-year-old left-handed opener Cook managed just 31 in this match, his runs came in 35 balls.
Only a few months earlier he had been left out of the World Cup squad on account of supposedly being unable to score quickly enough.
Cook then found himself labelled a "plodder" by former England captain Michael Atherton when promoted to the one-day leadership following Test skipper Andrew Strauss's decision to quit the shorter format.
Yet the 26-year-old left-handed opener's series return against Sri Lanka of 298 runs at 74.50, including a career-best of 119 at Lord's, and at a strike-rate of 96.75 backed up cricket great Sir Garfield Sobers's assertion that "Alastair Cook can play as good as any one-day player".
However, Ashes star Cook insisted barbs from the likes of Atherton had not provided him with additional motivation.
"I don't do it to prove anyone wrong," Cook said after a hard-fought victory in front of a capacity 19,000 crowd at a sun-drenched Old Trafford.
"I do it for the satisfaction that we got in that final half-hour of the game, and you can't replicate that. That's why you play the game."