Saud Shakeel hit his maiden double century in Tests as Pakistan stretched their lead to a dominant 149 against Sri Lanka on day three of the rain-hit opening match on Tuesday.

Sri Lanka bowled out the tourists for 461 in the final session after a frustrating ninth-wicket stand of 94 between Shakeel, who remained unbeaten on 208, and Naseem Shah, who made six off 78 balls.

The 27-year-old Shakeel, who is playing his sixth Test, ruled as he cut Dhananjaya de Silva for a boundary to bring up his double century to a standing ovation.

"When Naseem Shah joined me, he said that there's a chance for me to go for the double hundred," Shakeel told reporters after the marathon knock. 

"A lot of credit to him for backing me and not letting me panic."

The hosts ended the day on 14 for no loss after bad light stopped another rain-affected day. Sri Lanka still trail Pakistan by 135 runs in their second innings.

Nishan Madushka, on eight, and skipper Dimuth Karunaratne, on six, were batting at close of play.

The Sri Lankan bowlers led by off-spinner Ramesh Mendis, who ended with a five-wicket haul, hit back in the second session but Shakeel combined with the lower-order including a 52-run seventh-wicket stand with Noman Ali, who made 25.

But it was his 177-run partnership with Agha Salman, who hit 83, that drove Pakistan's bounce back from 101-5 in their reply to Sri Lanka's 312.

Both Shakeel, who was dropped twice on 93 and 139 as he went past his previous best of 125 not out, and Salman scored runs briskly and hit regular boundaries -- but the run rate dipped after Salman's departure.

"When I went in to bat, I wanted to attack If I had tried to be defensive we would have got bowled out for 150," said Shakeel. 

"That's the reason I attacked and was able to take the game deep."

Sri Lanka coach Chris Silverwood said: "I don't think we did our best with the ball. It's good to see Ramesh get five wickets haul which he deserved as a unit we weren't good as we could have been."

"We managed to control their run rate to an extent today but unfortunately, we missed a couple of key chances that cost us."

The day started late due to rain, which affected play on the previous two days, prompting officials to re-adjust the session timings.