Kevin Pietersen said he had "nothing to prove" after ending a run of 36 one-day innings without a century to help England beat Pakistan.
The former skipper, who scored only 67 runs in the Tests, hit an unbeaten 111 to earn England a nine-wicket win and a unassailable 3-0 lead in the series.
"Hundreds are hard work in one-day cricket, you don't get them all the time," said Pietersen.
"I don't have to prove points, I just want to enjoy my cricket."
Pietersen was playing in his 126th international, but had gone 39 matches without reaching three figures, dating back to November 2008 on the tour of India when he was captain of the side.
"This ranks right up there,'' the 31-year-old said, after scoring his eighth one-day ton.
"This Pakistan team is a fantastic cricket team. Our bowlers are phenomenal. Steven Finn - brilliant. Stuart Broad, James Anderson, Samit Patel, the guys have bowled fantastically well. When you have a team like that the batsmen only have to do a half-decent job.
"It's nice to get a hundred. Three-and-a-half years? I didn't realise it was that long. Only cricketers will understand that even though you're out of form, I knew I was in good nick. I was really calm.''
Pietersen expressed his delight at the way his team have turned their fortunes around in such emphatic manner following their 3-0 Test whitewash earlier this month to Pakistan.
"In terms of the team, the result is fantastic," he said. "To turn things around from the Test matches to win a series where England apparently don't do well is quite nice.
"It's pleasing for all the lads in the dressing room. The guys are really chuffed with what is going on.
"What we want to do is win our remaining games - but Twenty20 is a lottery."
Skipper Alastair Cook, who shared 170 with Pietersen, a record opening partnership for England against Pakistan, said: "It was a great start. It was nice to put a match-winning partnership together at the top of the order.
"Our bowlers were outstanding too. To keep them down to 222 on that wicket was a fantastic effort."
