Set a target of 184 to win, the World XI only managed 150-8 at Lahore's Gaddafi Stadium to concede the series to the home team by 2-1.
David Miller and Thisara Perera scored 32 each while Hasan Ali took 2-28.
Pakistan opener Ahmed Shehzad had earlier missed his second Twenty20 international century when he fell for 89. His 55-ball knock included eight fours and three sixes.
Babar Azam made a 31-ball 48 with five boundaries and added 102 for the second wicket with Shehzad.