Gul was 6-42 as England was bowled out for 218 with 26 balls left at the Oval in London. Abdul Razzaq took two wickets for the visitors, who trail the five-game series 2-1.
Fawad Alam was top scorer with 64 for Pakistan, which was bowled out for 241 after winining the toss and batting. Eoin Morgan had 61 for England and Luke Wright was 48 not out.
The fourth game will be played in three days at Lords in London.