The Dutch had surprised South Africa with a 38-run win in the cold and wet Himalayas on Tuesday but struggled to contain Sri Lanka in the heat of Lucknow.
As it happened | Scorecard
In their pursuit of 263 to win, Samarawickrama played a patient innings, hitting seven boundaries in his 107-ball stay at the crease, while Pathum Nissanka contributed 54 to help Sri Lanka reach the target with 10 balls to spare.
This victory marked Sri Lanka’s first points on the board in the 10-nation World Cup after earlier losses to South Africa, Pakistan, and Australia.
The Netherlands, on the other hand, now have one win and three losses from their four games.
Nissanka, opening the innings, reached his half-century in 52 balls with nine fours, making this his third consecutive fifty at this World Cup, following scores of 51 against Pakistan and 61 in the match against Australia.
The Dutch sensed a chance of another shock when Sri Lanka were 104-3 but Samarawickrama, who made a fine 108 against Pakistan, steadied the ship in a man of the match performance.
The 25-year-old had reached his 50 off 53 balls with four boundaries, putting on 77 in a key fourth wicket stand with Charith Asalanka (44).
Spinner Aryan Dutt was the pick of the Dutch bowlers with 3-44.
Earlier, Sybrand Engelbrecht and Logan van Beek hit maiden one-day international fifties as the Netherlands recovered from a poor start to post 262.
The 35-year-old Engelbrecht reached his milestone off 65 balls with three fours and one six.
Van Beek went to his fifty from 68 balls.
South African-born Engelbrecht and New Zealand native Van Beek helped the Dutch recover from 91-6, putting on a seventh-wicket partnership of 130.
It was a World Cup record for the seventh wicket bettering the 126 between Kapil Dev and Syed Kirmani against Zimbabwe in 1983.
The partnership ended when left-arm seamer Dilshan Madushanka clean-bowled Englebrecht for 70 with the score on 221.
Van Beek was eventually dismissed for 59 when he became recalled fast bowler Kasun Rajitha’s fourth victim.
Madushanka finished with figures of 4-49 while Rajitha had 4-50.
Worryingly for the Sri Lankans, they coughed up 33 extras, 26 of which were wides.
After winning the toss and choosing to bat, the Netherlands saw Rajitha send back Vikramjit Singh (four), Max O’Dowd (16) and Colin Ackermann (29) as they slipped to 54-3.
Madushanka picked up Bas de Leede (six) and Teja Nidamanuru (nine), before spinner Maheesh Theekshana grabbed the key wicket of skipper Colin Edwards (16).
The Dutch went 20 overs without hitting a boundary before Engelbrecht and Van Beek launched their rescue act.
(With AFP Inputs)