Ravi Bopara scored 39 and Umar Gul took three wickets as England were restricted on 136-6.
Earlier Pakistan set England a target of 145 runs to clinch the first T20 cricket match.
Shoaib Malik top-scored for Pakistan with 39 as the Green Shirts made 144-6 after losing the toss. Graeme Swann with 3-13 was England's most impressive bowler.