Eoin Morgan was also in great form as the captain scored an unbeaten 71 off 48 balls. England must improve their bowling since the batting may not always bail the team out. "He was brilliant and the difference in the two teams".
Their defeat in the second one-day global to England extended Pakistan's winless streak, but there were positive signs from which they will look to draw confidence heading into the third match on Tuesday, 14 May.
Buttler's 50-ball century was the epitome of improvised, aggressive stroke play.
Fakhar provided their main threat with 12 fours to go with four maximums, but he was caught behind by Buttler chasing a wide delivery and Pakistan's hopes were dented further when Babar Azam (51) followed five balls later. Zaman too got a 130 odd as the pitch was flat to bat.
Top-ranked England are hosting the 2019 tournament and have boosted a winning side with the inclusion of all-rounder Jofra Archer in their warm-up matches.
Buttler did not arrive at the crease until the 36th over but once again showed how seamlessly he moves through the gears from a standing start - his career strike rate of 119.88 is the highest of any batsman to have played 100 one-day worldwide innings. Sure, he lacks experience, but with Buttler the one bona fide "crackerjack cricketer" among the batsmen, Archer is the one man now, among the bowlers, who has the potential to reach that status.
After the 28-year-old's incredible innings on Saturday, Nasser Hussain declared he could take his place among the all-time greats of the format - AB de Villiers, Vivian Richards, and MS Dhoni.
Actually, his batting is a combination of Dhoni and De Villiers - the inventiveness, improvisation and hand-eye co-ordination of the latter melded to the cool, nerveless presence of the former, especially when prosecuting run-chases.
Imam carries the burden of being the nephew of Pakistan great and current chief selector Inzamam-ul-Haq, but there is no denying he is a fine player in his own right.
That super-fast decision making is the real genius of Buttler among a range of very special skills.
The 50-ball effort in victory over Pakistan at the Ageas Bowl on Saturday was four balls slower than his best against the same opposition in Dubai four years ago but England's vice-captain feels his array of power and precision strokes are in tune to up the ante.
The reports in ESPNCricinfo have revealed that he missed the second ODI due to the viral infection but will now also not play the third match which is set to be played on Tuesday in Bristol.