A superb all-round performance by Shahid Afridi put Sri Lanka's world No. 1 ranking on the line as Pakistan recorded a three-wicket victory in their first Twenty20 international on Wednesday.
Man-of-the-match Afridi hit three sixes and two fours in his unbeaten knock of 39 off 20 balls and guided Pakistan to 146-7 with five balls to spare.
Earlier, Afridi bowled a tidy spell of 1-20 despite Angelo Mathews hitting a 34-ball 50 which spurred Sri Lanka's total to 145-5.
Opening batsman Sharjeel Khan (34) and Pakistan captain Mohammad Hafeez (32) also made useful contributions, before Afridi stood firm against Lasith Malinga's late burst of 3-26.
Sri Lanka could lose its No.1 spot to Pakistan if it loses the second and final match of the series on Friday.
Afridi, often being criticized for throwing away his wicket with irresponsible shots, played intelligently and ensured Pakistan's victory after Malinga took three wickets in his last three overs.
Afridi lofted medium fast bowler Nuwan Kulasekara for two sixes in one over and paddle swept the same bowler for a six over fine leg for the winning runs.
"Pakistan won and I'm very happy for that," Afridi said. "I have to mention Mohammad Hafeez, who was not feeling well but still he played for the country."
As for his own performance, Afridi said: "The bowling was good, but I want to be more consistent in my batting."
Sri Lanka had some fine moments in the field with Lahiru Thirmanne plucking an airborne two-handed catch to dismiss in-form Ahmed Shehzad (4) in the third over. Tillakaratne Dilshan terminated a 57-run second wicket stand when he held onto a one-handed catch off second attempt at long on to dismiss Khan.
Unorthodox spinner Ajantha Mendis then took two wickets by having Hafeez leg before wicket and running out Umar Akmal (5) as Pakistan slipped to 76-4 in the 12th over.
Umar Amin was brilliantly caught at midwicket by captain Dinesh Chandimal in Malinga's return spell.
Earlier, after electing to field first, spinners Saeed Ajmal (2-35) and Afridi tied down the Sri Lanka top order before Mathews upped the ante in the last three overs. He added 58 runs off 34 balls with Thirimanne for the fifth wicket stand against some wayward bowling.
Ajmal had the key wickets of Kusal Perera (15) and Kumar Sangakkara (21) and in between Afridi trapped Chandimal (22) leg before wicket.
Mathews survived a confident lbw appeal off Afridi when on 17 before he smashed fast bowler Bilawal Bhatti for three boundaries in the 18th over. Thirimanne (23 not out) ruined Ajmal's bowling figures by hitting the offspinner's last ball of the spell over midwicket for a big six.
Mathews completed his only second Twenty20 half century with a straight boundary off Sohail Tanvir's (2-34) last over but off the next delivery Khan took a smart catch on the edge of wide mid-wicket boundary.