The hosts made a brave bid to chase down 270, reaching 132 for two by tea on the Day V, before they were pegged back by a three-wicket burst from off-spinner Saeed Ajmal.
Dinesh Chandimal scored 65 and the prolific Kumar Sangakkara returned unbeaten on 74 as Sri Lanka made 195 for four before the game was called off with nine overs remaining at the Pallekele International Stadium.
The 1-0 scoreline — following a 209-run victory in the first Test in Galle — was Sri Lanka’s first Test series win since beating New Zealand 2-0 at home in 2009. “A lot of hard work has gone into this series win. It’s not that we did not play good cricket earlier, but somehow the results did not show that. So it was important to win against a quality side like Pakistan. It will make the youngsters more confident, but we need to keep improving as a unit,” he said.