Pakistan held on to record an 11-run victory in the opening one-day international despite some lower-order heroics from Sri Lanka in Sharjah.
Sri Lanka seemed set to fall well short of Pakistan's total of 322-5 before Seekkuge Prasanna and Sachithra Senanayake both smashed 42 runs from 25 and 24 balls respectively.
But three untimely late wickets meant the tourists ultimately came up short, meaning they fall 1-0 behind in the five-match series in the United Arab Emirates.
Pakistan's commanding total was built on the back of a hundred from Mohammad Hafeez and a half-century from Sohaib Maqsood, while Shahid Afridi blasted what proved to be 34 vital runs from 12 balls late on.
The tourists needed just 15 off eight balls before Senanayake swatted Sohail Tanvir to substitute fielder Anwar Ali, who caught the ball at the second attempt, with Sri Lanka losing their last two wickets in the final over to fall to 311 all out.
It was a fantastic rearguard effort from the lower order pair, both of whom made 42, but it will be of little consolation as Pakistan drew first blood in the five-match series.
Pakistan, having opted to bat first, were grateful for the efforts of Hafeez, who hammered seven fours and four sixes en route to a fine 122 off 129 balls.
He came to the crease after Lakmal (2-73) made an early breakthrough when Ahmed Shehzad was trapped lbw for 11 in the seventh over.
Khan and Hafeez then added 83 for the second wicket, with the debutant playing the lead role.
Khan crashed three sixes in his run-a-ball 61 before he was plucked on the boundary edge off leg-spinner Seekkuge Prasanna.
The backbone of the innings was then set by Maqsood and Hafeez, who brought up his century by hitting Lakmal straight down the ground for six from his 111th ball.
The veteran was perhaps at fault for Maqsood's departure as he failed to keep up with his request for a second run, sending him back to be run-out having made 73 off 68 deliveries.
It only prompted late fireworks from Afridi, who ensured a formidable total by clearing the ropes three times to blast his way to 34 off 12 balls, before he and Hafeez were dismissed late on by Thisara Perera and Suranga Lakmal respectively.
Kusal Perera and Tillakaratne Dilshan put on 66 to get Sri Lanka off to a steady start in reply before the latter fell after pulling Junaid Khan to deep square-leg to depart for 30.
Perera kept the score ticking along but perished for 64 after being trapped in front by Hafeez, while Sri Lanka's star batsman Kumar Sangakkara was strangely subdued before edging behind a wide delivery from Afridi, who had Lahiru Thirimanne caught on the deep square-leg boundary.
Dinesh Chandimal (46) and Angelo Mathews (31) combined to keep Sri Lanka in the game but both were dismissed in the space of six balls.
The tourists' hopes looked to be over after the dangerous Thisara Perera had struck Bilawal Bhatti to cover and although Prasanna and Senanayake ensured a dramatic conclusion, their efforts proved too little too late as Sri Lanka were all out after 49.4 overs.