Mohammad Hafeez saluted Pakistan's "total team effort" after they stunned hosts England with a 14-run victory over the tournament favourites at Trent Bridge on Monday.
Hafeez earned the man-of-the-match award for his influential innings of 84 from 62 balls as he punished England for dropping him when he was on 14.
The 38-year-old also took the key wicket of England captain Eoin Morgan, slowing the run chase before Pakistan held on despite centuries for Joe Root and Jos Buttler.
It was a remarkable result for Pakistan, who made 348-8, just days after they were thrashed by the West Indies in their first match of the tournament at the same venue.
On that occasion, Pakistan were bowled out for just 105, but they proved a much tougher against England and Hafeez put that down to the whole squad sticking together and producing their best at key moments.
"Everyone was believing we could do this. We were playing good cricket but not winning crucial stages of the game," he told Sky Sports.
"Everyone chipped in today and gave everything which was required to win the game.
"We needed one winning performance and then everyone contributed accordingly. It was a total team effort. It is a very happy dressing room."
Pakistan captain Sarfaraz Ahmed echoed Hafeez's assessment of his unpredictable team's against-the-odds triumph and singled out leg-spinner Shadab Khan.
"It was a great team effort. Bowlers bowled really well. We tried a couple of different things. We started with Shadab because we know their openers are not good against spin," he said.
"Fielding is a very important part. In the last ODI series it was different. Today we feel better and we bowl better."
- Bitter blow -
It was a bitter blow for England after they made a flying start by crushing South Africa in their opening game.
That 104-run win was hailed as proof that England, the ICC's top ranked one-day international side, could win the World Cup for the first time.
Root admitted England had only themselves to blame for an unusually sloppy display featuring dropped catches and careless dismissals.
"Very disappointed if I'm being honest. One thing we have to make sure we don't do is panic and go away from what's been so successful for us," Root said.
"Credit to Pakistan, they played some really good stuff, I thought it was a great game of cricket.
"We probably just left a little too much to do at the end. That's probably my fault."
Insisting England will emerge stronger from their surprise defeat, Root added: "We've been nowhere near our best cricket throughout these two games, so with that still to come we feel like we're in a good place."
