Cook congratulates England's top-scorer Paul Collingwood
Captain Alastair Cook said England needed to make improvements in certain areas after going 1-0 up in the one-day series in Bangladesh on Sunday.
England reached a modest target of 229 in Mirpur with 24 balls to spare but only after Tamim Iqbal (125) had given the home team a brilliant start.
Cook said: "It was tough up front when Bangladesh took the game away from us.
"But once we got a couple of wickets we fought back well and in the end it was a comfortable enough win for us."
Cook, standing in for Andrew Strauss who is remaining in England for the duration of the three ODIs and two Test matches, had plenty of concerns when Tamim and Imrul Kayes raced to 63-0 from the first nine overs.
But England's bowlers improved considerably from then on, and the tourists' batsmen were never under any sustained pressure when it came to their turn to bat.
Cook applauded the innings of 20-year-old Tamim, saying: "It's the first time we've seen him play and he hit some amazing shots. But the bowlers stuck at their task and we took some vital wickets at vital times."
Asked why England had opted against a second spinner in James Tredwell, Cook said: "It was a very strong option but the way we have played with our three quicks recently in one-day cricket we felt that was the way to go."
Though later upstaged by Paul Collingwood (75 not out), Cook (64) set the tone with a bright response in England's run chase.
"It's important to start quickly as when the ball gets soft on these wickets it's harder to get a move on. Colly keeps delivering the goods at crucial times. But this is just one game out of three and there are still a few areas we can improve on."
Man-of-the-match Tamim said: "It was a nice track for batting but we lost quick wickets and had to slow down. There are lots of things to improve on in my batting and I'm working on it, but I'm happy enough to get a century and hope there will be more."
Defeated skipper Shakib Al Hasan said: "We should have scored 270, 280 because we had a very good start. Our middle order didn't get enough big scores, that was our problem.
"Tamim is scoring regular runs for us at the top of the order and is our best batsman in ODIs. Good luck to him but we need to support him in the middle and lower order.
"I think our spinners bowled well but Cook and Collingwood played really well against them."
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