Smith tonked two sixes and nine fours in a defiant innings of 68 from 90 balls, the innings' top score, and threatened at least to deny the Lankans their bonus point.
The right-hander was involved in two vital partnerships, adding 46 runs with Denesh Ramdin (29) for the seventh wicket but more destructive was his 43-run stand with Deighton Butler (13 not out) that came in less than seven overs.
Smith's innings came to a tame end when he played on to his stumps a Muttiah Muralitharan delivery in the 44th over.
The Caribbean islanders were eventually all out for 191, two short of the target to deny the hosts a bonus point, in 45.1 overs.
The second string West Indies side however were done in by the the early jolts inflicted by speedster Farveez Maharoof, who returned with brilliant analysis of three for nine, and Dilhara Lokuhettige (2-30).
Muralitharan's 2-46 was not his usual economical figures but the bowler to suffer the most from Smith's blade was Upul Chandana (1-65).