Sri Lanka stunned Pakistan by 35 runs in the second Twenty20 international in Lahore on Monday.
The visitors had set a target of 183 runs for Pakistan to save the series, but the hosts were bowled out for 147 with one over to spare.
Rajitha sent Fakhar Zaman (6 runs) back to the pavilion while Pradeep took the wicket of Babar Azam (3 runs) in the third and fourth overs, respectively. The eighth over of the innings was the most disastrous for the host team as Hasaranga dismissed Ahmed Shehzad (13), Umar Akmal (0) and skipper Sarfaraz Ahmed (26) on the third, fourth and sixth ball of the over.
Udana took the wicket of Imad Wasim (47) in the 16th over, while Pradeep sent Wahab Riaz (7) back on the last ball of the 17th over. Udana also dismissed Shadab Khan (0) on the first ball of the 18th over while Pradeep sent Asif Ali (29) and Mohammad Hasnain (1) away in the 19th over.
Earlier, Bhanuka Rajapaksa smacked an aggressive maiden half-century as the visitors made 182-6 against Pakistan.
The 27-year-old left-hander, playing only his second T20I, blasted 77 off 48 balls in an innings featuring six sixes and four boundaries after Sri Lanka won the toss and batted.
Rajapaksa added 94 for the third wicket with Shehan Jayasuriya, who made a 28-ball 34 with four boundaries.
Sri Lanka kept the same team which upset Pakistan, the world's number one T20 team, in the first match by 67 runs on Saturday.
The Green Shirts, who had never lost a T20 series in six attempts to Sri Lanka before today, brought in paceman Wahab Riaz and opener Fakhar Zaman in place of Iftikhar Ahmed and Faheem Ashraf.
The third and final match will be played at the same venue on Wednesday.
Pakistan: Sarfaraz Ahmed (captain), Ahmed Shehzad, Babar Azam, Umar Akmal, Asif Ali, Fakhar Zaman, Imad Wasim, Wahab Riaz, Mohammad Amir, Mohammad Hasnain, Shadab Khan
Sri Lanka: Dasun Shanaka (captain), Danushka Gunathilaka, Avishka Fernando, Shehan Jayasuriya, Bhanuka Rajapaksa, Minod Bhanuka, Wanindu Hasaranga, Lakshan Sandakan, Isuru Udana, Nuwan Pradeep, Kasun Rajitha
Umpire: Aleem Dar (PAK) and Ahsan Raza (PAK); Tv umpire: Shozab Raza (PAK); Match referee: David Boon (AUS)