Bhanuka Rajapaksa's unbeaten 71 and Wanindu Hasaranga's key contributions with both bat and ball fired Sri Lanka to their sixth Asia Cup title with a 23-run win over Pakistan on Sunday.

Fast bowler Pramod Madushan (4-34) and Hasaranga (3-27) shared seven wickets between them to bowl out Pakistan for 147 while chasing 171 in Dubai.

Earlier the left-handed Rajapaksa put on a key 58-run stand for the sixth wicket with Hasaranga, who hit 36, to help Sri Lanka to 170-6 after being in trouble at 58-5.

Sri Lanka, who had to abandon plans to host the competition due to political unrest, bounced back from an embarrassing opening defeat by Afghanistan to win the tournament, a curtain-raiser for next month's T20 World Cup in Australia.

Pakistan skipper Babar Azam won the toss, choosing to field first with nine of the previous 12 matches won by the teams chasing.

But Sri Lanka bucked the trend as the island nation overcame an inspired opening spell of bowling by Pakistan quicks Naseem Shah and Haris Rauf.

Rajapaksa and Hasaranga rebuilt the innings and regularly found the boundary to up the scoring rate.

Rauf dismissed Hasaranga, who hit five fours and one six in his 21-ball knock, caught behind for his 50th T20 wicket to break the dangerous stand.

Rajapaksa kept up the attack and survived a dropped catch by Shadab Khan in the deep, soon reaching his third T20 half-century.

Rajapaksa, who finished the innings with a four and six off Naseem in his 45-ball blitz, and Chamika Karunaratne put on 54 runs to further boost the total.

Dilshan Madushanka bowled a shaky opening over, starting with a no-ball and four wides, but the left-arm quick swiftly made amends.

Playing just his second T20, Madushanka had Azam caught at short fine-leg for five and then bowled Fakhar Zaman for a first-ball duck the following delivery.

Mohammad Rizwan (55) and Iftikhar (32) put together a partnership of 71 but Madushan broke the stand with the wicket of Iftikhar.

Rizwan, who surpassed India's Virat Kohli as the highest run-getter of the tournament with 282, reached his fifty with a six off Chamika Karunaratne but soon fell to Hasaranga's leg-spin and the wheels came off the chase.

Karunaratne got Rauf out on the final ball to trigger Sri Lankan celebrations. (AFP)