Young Jonny Bairstow and Steven Finn inspired England to a 38-run victory.
Man of the match Bairstow made an unbeaten 60 in 46 balls with the help of five fours and two sixes and helped England to make 150 runs in 20 overs.
Opener Craig Kieswetter also chipped in with 31 off 24 deliveries while Pakistan seamer Umar Gul took two for 31 and spinner Saeed Ajmal produced an economical spell of one for 20 in four overs.
Pakistan started their run chase badly, slumping to two for two after losing Mohammad Hafeez for a duck and Asad Shafiq for one. Wickets continued to fall at regular intervals and Shahid Afridi top-scored with 25 in 23 balls as Pakistan were bowled out for 112 in 18.2 overs.
England captain Stuart Broad and spinner Graeme Swann took two wickets apiece but improving young paceman Finn stole the show by returning figures of three for 30.
The third and final match will be in Abu Dhabi on Monday.