Sri Lanka's inexperienced cricket team overcame a poor start with bat and ball to put on an impressive all-round show Sunday and win the Asia Cup for the sixth time with a 23-run victory over Pakistan.

Bhanuka Rajapaksa hit an unbeaten 71 off 45 balls in Dubai and led Sri Lanka as it recovered from 58-5 to reach 170-6 in the final after Pakistan won the toss and elected to field.

Pakistan crashed to 147 all out off the last balls as its top order continued to struggle against the pace with fast bowler Pramod Madushan claiming 4-34 in only his second T20 international.

Leg-spinner Wanindu Hasaranga then baffled the lower order with his sharp googlies to accelerate Pakistan's collapse.

Hasaranga, who earlier scored 36 off 21 balls, had Pakistan's top-scorer Mohammad Rizwan (55) caught in the deep in his last over before claiming the wickets of Asif Ali and Khushdil Shah in the same over to finish with 3-27.

"It was all about nerves, I knew the youngsters can always deliver," Sri Lanka skipper Dasun Shanaka said. "We have players with good caliber, and they stood up well."

Sri Lanka had an awful bowling start when left-arm fast bowler Dilshan Madushanka conceded nine runs through a no ball and several wides before the 21-year-old's first legitimate delivery at the sixth attempt.

Madushan, who made his T20 debut in the last Super 4 match against Pakistan on Friday, settled his team's nerves quickly by claiming the wickets of Babar Azam (5) and Fakhar Azam (0) off successive deliveries inside the powerplay.

Babar was brilliantly snapped up by Madushanka over his head at short fine leg off a hard flick and Fakhar went for a golden duck by dragging the first ball onto his stumps.

Babar, the second-ranked T20 batter, ended the tournament with only 68 runs in six games.

"As a batting unit we didn't perform according to our potential," Babar said. "We didn't finish the way we would have wanted to and gave away 15-20 extra runs ... the more you learn from these ups-and-downs is good, but you need to reduce your mistakes."

Rizwan and Iftikhar Ahmed (32) added 71 runs for the third wicket in almost 10 overs as Sri Lanka kept mounting the pressure by bowling tidily in the middle overs.

Madushan broke the stand in his return spell as Pakistan collapsed from 102-3 to lose its last seven wickets for 45 runs with Sri Lanka fielders holding onto all their catches.

Earlier, Pakistan's fearsome pace attack, led by Haris Rauf (3-29), had Sri Lanka in trouble inside the first nine overs before Rajapaksa and Hasaranga led the recovery.

Rajapaksa hit six fours and three sixes in his innings.

Fast bowler Naseem Shah (1-40) had Kusal Mendis clean bowled off the first ball with a stunning inswinging delivery while Rauf dismissed Pathum Nissanka and Danushka Gunathilaka.

But Rajapaksa and Hasaranga counterattacked after having negotiated the spin threat of Shadab Khan (1-28). Surprisingly Babar used his premium left-arm spinner Mohammad Nawaz for only one over which went for three runs as both Sri Lanka batters cut loose against the pace of Shah and Mohammad Hasnain (0-41).

Pakistan was scrappy in the field as Rajapaksa was dropped either side of his half century by Shadab in the deep. Rauf had Hasaranga caught behind in the 15th over, but Rajapaksa added a further 54 runs in the last five overs with Chamika Karunaratne, who made 14 not out.

Rajapaksa provided Sri Lanka with a late flourish when he smashed Shah for a boundary off the penultimate ball and then smashed a six over extra cover to give Sri Lanka a strong total to defend.

Sri Lanka made a stunning comeback with five successive wins in the tournament after getting beaten by Afghanistan in its opening game. Sri Lanka also beat Pakistan in the last Super 4 game.