Earlier, Young Hussain Talat struck a fine fifty to help Islamabad United to a modest total of 165 runs for six wickets. The 20-year-old left-handed batsman blasted 56 off 39 balls with six fours and two towering sixes.
Sent into bat, Islamabad United lost Steve Smith for a duck but then came Talat and rescued his team, adding 60 runs for the second wicket together with the 40-year-old Rafatullah Mohmand.
Later, captain Misbah-ul-Haq (25), Brad Haddin (22) and Shane Watson (29) made valuable contributions to take the total to some respectability.
Spinner Zulfiqar Babar and pacer Anwar Ali claimed two wickets each for Quetta Gladiators.
Gladiators made two changes in their team, replacing Mills and Hamza with Perera and Zulfiqar.
Islamabad United also made two changes, bringing in Badree and Talat in place of Duckett and Amad.
Quetta Gladiators: Sarfraz Ahmed (captain), Umar Gul, Asad Shafiq, Ahmed Shehzad, Mohammad Nawaz, Kevin Pietersen, Luke Wright, Rilee Rossouw, Mahmudullah Riyad, Anwar Ali, Tymal Mills, Hassan Khan, Nathan McCullum, Thisara Perera, Bismillah Khan, Mir Hamza, Zulfiqar Babar, Saad Nasim, Umar Amin, Noor Wali
Islamabad United: Misbah-ul-Haq (captain), Shane Watson, Steven Finn, Mohammad Irfan, Samuel Badree, Mohammad Sami, Brad Haddin, Sam Billings, Hussain Talat, Amad Butt, Dwayne Smith, Ben Duckkett, Shadab Khan, Zohaib Khan, Saeed Ajmal, Imran Khalid, Asif Ali, Rumman Raees, Syed Muzammil Shah