Pakistan skipper Babar Azam said on Thursday his team's latest Test hero Saud Shakeel had stepped up his game and showcased new shots in his match-winning unbeaten 208 against Sri Lanka.

The visitors won the first Test in Galle by four wickets after opener Imam-ul-Haq hit an unbeaten 50 to anchor a tricky chase of 131 on the final day to lead the two-match series 1-0.

But left-handed batsman Shakeel was the star after his maiden Test double century powered Pakistan to 461 all out and a handy first-innings lead of 149.

His 177-run partnership with Agha Salman, who hit 83, helped Pakistan bounce back from 101-5 in their reply to Sri Lanka's 312.

"Saud has improved a lot. He has been working hard after the New Zealand series," Azam said of the man of the match.

"He attended two camps in Lahore and Karachi. I spoke with him and he told me he had developed a few shots which he applied in this innings.

"As captain, I am very satisfied with his performance. When he came to bat we had lost four wickets and Saud and Salman built the partnership."

Azam added: "When your team-mate performs well and your team wins the match it gives a lot of confidence, especially in different conditions, and youngsters like Saud, Salman and Abrar Ahmed stepped up and performed."

Shakeel looked assured in his stroke-making in his marathon knock and then a cameo of 30 on the fifth day.

Pakistan spinners Noman Ali and Abrar took three wickets each and Salman chipped in with two from his off-spin to bowl Sri Lanka out for 279 on day four.

Dhananjaya de Silva stood out for Sri Lanka with his 122 in the first innings and then 82 in the second but the rest of the batting faltered.

Skipper Dimuth Karunaratne acknowledged their batting had flopped.

"In this match, all our main batters didn't make runs," Karunaratne told reporters.

"Usually two-three batters performed in the top seven, but apart from Dhananjaya's contribution there was nothing big from the rest."

The second Test starts in Colombo on Monday.