Match in played at Gaddafi Stadium Lahore, Karachi Kings captain Babar Azam won the toss and invited Islamabad to bat first.
IU scored 191 runs for the loss of 7 wickets in the stipulated 20 overs. Capt Shadab Khan remained prominent by scoring 34 runs.
Islamabad United opener Rehmanullah was dismissed for 12 runs while Mohammad Akhlaq returned to the pavilion for just two runs.
Alex Hales was dismissed for 25. Liam Dawson 15 Azam Khan 22 Asif Ali 28 runs Faheem Ashraf scored 29 runs off 10 balls.
Karachi Kings for Emad Wasim took two wickets while Mir Hamza Chris Jordan and Ameed Asif took one wicket each.
In pursuit of the target, Karachi Kings scored 190 runs for the loss of 7 wickets in the stipulated overs.
The Karachi Kings suffered a setback at the start of the innings when capt Babar Azam was dismissed for just 13 runs. Sahibzada Farhan walked for 17 off 21 balls.
Sharjeel Khan also made 44 off 29 balls while Qasim Akram made 51 off 26 balls.
Emad Wasim was also dismissed for 55 off 28 balls while Muhammad Nabi was also dismissed for three off three balls.
Waqas Maqsood took 3 wickets for Islamabad United while Asif Ali took 2 wickets and Liam Dawson and Zeeshan Zameer took one wicket each.
IU defeated Karachi Kings by one run after a thrilling contest. This defeat is the seventh consecutive defeat of Kings in the current season of PSL due to which Karachi Kings is out of the knockout stage of PSL 7.