Eoin Morgan's brilliant 89 helped England overcome Australia by 15 runs in the opening ODI of the series at Lord's.
Michael Clarke made 61 for Australia as they pushed England close in an even contest, but in the end the tourists' left it too late in a chase of 273.
Earlier, Morgan's unbeaten knock featured four sixes and five fours - three of the maximum's coming in consecutive deliveries faced by the left hander, as Brett Lee and Shane Watson came in for some treatment late on.
He managed to drag the hosts to a score of 272/5 on a good pitch, but with England having moved along conservatively through the middle of their innings. After reaching 50 in 45 balls, the number five accelerated superbly in a partnership of 83 with Craig Kieswetter.
Australia made a strong start to their chase, with David Warner looking in particularly good form. James Anderson's quick double to remove him and George Bailey put England on top, and despite a fine partnership between Clarke and Matthew Wade, they were always chasing the game.
Ebb and flow
Michael Clarke won a potentially crucial toss under ashen skies in north-west London, and with the threat of rain ensuring the groundstaff were on red alert for prior to the start.
Cook and Bell got off on time, but were interrupted after just 2.2 overs for the first of three breaks for squally showers. It was a disruptive period for England's openers, but with such a technically sound pair at the crease, they overcame the test superbly.
Bell in particular was in fine form, successfully surviving a review when he was incorrectly given out caught behind and treating the Lord's capacity crowd to some silky shots. With the score on 74 and Australia desperate for a breakthrough though Clarke recalled Brett Lee to the attack and the veteran immediately trapped Bell LBW. Replays suggested a small inside edge, but this time Bell chose not to review.
It put the Australians on top, and by the time Pat Cummins made Cook his first international scalp in England and Ravi Bopara had come and gone for just 16, England had been well and truly pegged back.
Jonathan Trott divides opinion like few other cricketers, but even his harshest critic would have admitted his innings was played at the perfect tempo.
Alongside Morgan, with whom he put on 68, Trott accumulated well with little flamboyance, ticking to his 16th ODI half century in 63 balls before being bowled by left-arm spinner Xavier Doherty - who was far more impressive bowling against the spin from the Pavilion End than with it at the Nursery - for 54.
Morgan started in similarly circumspect mood, but such is his range of shots that he was soon manipulating the field and scoring quicker than a run a ball. He and Craig Kieswetter appeared to be struggling to get the ball away, until Morgan finally exploded in the 47th over.
Lee, often the master at the death, was dispatched over long on twice in consecutive deliveries, as the Irish-born number five was afforded some width to free his arms. Kieswetter finally found the boundary first ball of the next over, and Morgan hit the next ball he faced for another six - Watson dispatched for 19.
It was the kind of finish England needed, with Morgan wracking up an astonishing 34 from the final 11 balls he faced.
Australia's response started well, before Finn dismissed Watson with one which he feathered through to Kieswetter. Watson was initially given not out, but England chose a good time to use their review, with Hot Spot indicating there was an edge.
At the other end David Warner was illustrating why he's one of the best all-round batsmen in the game with an innings full of clinical strokeplay. He and George Bailey looked comfortable on a largely flat pitch, before James Anderson turned the match on its head.
England's premier fast bowler appeared to be suffering from groin problem, but after looking uncomfortable bowling one ball, he dismissed Bailey with the next, as Australia's ODI skipper dragged on onto his stumps.
After being seen by a physio after that over, it was a surprise when Anderson took the next one, but he delivered perhaps the defining blow as Warner flashed at one without moving his feet and was wonderfully caught by a diving Kieswetter.
From bright sunshine the weather once again went overcast and the rate ramped up for the tourists. David Hussey was bowled when the ball became tangled in his protective gear and dropped onto the stumps, and Bresnan tempted Smith to edge through to Kieswetter.
Clarke and new wicket-keeper Wade were excellent in their response to a stiff target, but once Wade was run out in a mix up with his captain, there was little doubt in the result.
Brett Lee's 29 admirably kept the game alive until the final 3 balls, but on failing to hit three sixes the win was England's.