Junaid and Hasan took three wickets each as Pakistan wrapped struggling Sri Lanka for 236 runs in 49.2 overs.
Pakistan's pace army, led by Junaid Khan, hit the right chords at Cardiff as they wrapped struggling Sri Lanka for a paltry 236 runs in 49.2 overs in a must-win ICC Champions Trophy tie on Monday.
Junaid and Hasan Ali took three wickets each to help Pakistan step closer to the semi-final.
Junaid took the scalp of Danushka Gunathilaka (13), Dhananjaya de Silva (1) and Thisara Perera (1), while Kusal Mendis (27), Asela Gunaratne (27) and Suranga Lakmal (26) became the victims of 23-year-old Hasan Ali.
Amir continued the rhythm, dismissing Niroshan Dickwella and Sri Lankan captain Angelo Mathews for 73 and 39 runs respectively.
The Islanders found their foundation in the opener's 73-run knock that came off 86 balls. No other Lankan managed to hit a 50-plus knock after the dismissal of Dickwella.
Pakistani fast bowler Fahim Ashraf also chipped in with dismissing Dinesh Chandimal and Nuwan Pradep for duck and 1 run respectively.