Mohammad Sami successfully defended 19 off the last over, including a hat-trick to defeat Peshawar Zalmi by 12 runs.
When Wahab Riaz smashed the first ball of the over for a six, the equation looked a lot simple for Zalmi with 13 needed off five balls. But he was caught in covers the next ball off a wide slower ball from Sami. Umaid Asif was the next one to go after he was caught at long off by Faheem Ashraf - for a moment it looked like the ball will sail over the ropes before it landed in the hands of Faheem. Hasan Ali was the third one to fall as Sami completed his hat-trick, with Sahibzada Farhan backtracking from covers to take the catch.
Sami finished with the figures of three for 22. The three other players to take hat-tricks in PSL include Mohammad Amir, Imran Tahir and Junaid Khan.
Zalmi, chasing 159-run target were propelled by a fiery 22-ball 51 by Pollard with five sixes and three boundaries but as the asking rate surged he fell in the 17th over and with it Peshawar's hopes faded.
Musa took 3-25. This is Peshawar's sixth loss in nine matches against Islamabad in all PSL editions.
Islamabad ended up on 158-9 in their 20 overs with Ian Bell scoring a patient 46-ball 54 and 18-ball 29 by Cameroon Delport who hit two sixes and a boundary.
Pollard added 55 quickfire runs with Darren Sammy (11) as Peshawar needed 58 in the last five overs. Pollard hit two sixes and a four off spinner Samit Patel and then another two off Shadab Khan to give a real scare to Islamabad.
But he holed out to Faheen Ashraf who took 2-32.
It was young 18-year-old debutant Musa who shook Peshawar Zalmi innings with wickets of Kamran Akmal (7), Dawid Malan (1) and Sammy to prove he has the talent to make his name from the PSL.
The win gives Islamabad their second win in four matches. They are now third in points table which is topped by Quetta Gladiators who have six points from three wins in as many games. Peshawar are second with four points in four matches but with a better net run-rate than Islamabad.
It was once again the pace which worked well for Peshawar as Sameen Gul recorded his best PSL figures of 3-29 and Hasan (2-29) who rocked Islamabad's top order after they were sent in to bat.
Sameen removed Luke Ronchi (21) and Sahibzada Farhan (15) in his first spell. Once Hussain Talat was removed for a duck, Bell and Deloprt steadied the innings through their fourth-wicket stand of 56.
Hasan broke the stand with the wicket of Delport.
Asif Ali looked dangerous as he hit two sixes in his five-ball 13 but played one shot too many before falling to Sameen in the 16th over.
Islamabad managed 44 in the last five overs but lost five wickets in the process. Bell was finally run out in the penultimate over but his steady innings that gave Islamabad something to fight on.