Chasing 133 to win, Sri Lanka registered their first win over Pakistan in the new-style, wham-bang format with six balls to spare.
He may be pushing 40 years old but Jayasuriya (40 runs) showed little sign of ageing as he and fellow opener Mahela Udawatte (25) put on 66 in 6.
6 overs.
They took advantage off a wayward Pakistan attack with Shoaib Akhtar, Sohail Tanvir and Umar Gul being hit to all parts of the ground in front of 9,000 fans at King City.
Jayasuriya was particularly harsh on Akhtar, flicking the recalled quick for four in his first over and then pulling him for consecutive sixes over midwicket.
Desperate Pakistan, who had won the group match between the two sides by three wickets on Saturday, turned to spin and Shahid Afridi dismissed Udawatte while Shoaib Malik accounted for Jayasuriya.
But despite losing skipper Mahela Jayawardene for just five, Kaushalya Weeraratne (12) and Chamara Kapugedera (17 not out) saw Sri Lanka home.
Earlier Mendis, 16 year