BASSETERRE, St. Kitts (CMC):
The right-handed Joseph struck 86 but the regional side collapsed to 230 all out in 47.4 overs, as they chased down Sri Lanka's 250 for seven made in the 50 allotted overs.
Joseph faced 120 balls, struck eight fours and one six but was the only West Indies A batsman to get a start and carry one.
Austin Richards Jr. struck 32 from 49 balls with four fours while the left-handed Ryan Hinds chipped in with 31 from 53 balls.
Patrick Browne played a cameo 26 from 13 balls at the death but lacked support as Sri Lanka seized the initiative.
Windies A started poorly in their run chase, losing in form opener Devon Smith for one with the score on six, and Travis Dowlin for two, six runs later, both batsmen were dismissed by pacer Ruchira Perera.
Joseph and Richards then formed a 58-run third wicket stand to steady the innings before Richards was caught at the wicket off fast bowler Ishara Amarasinghe.
Hinds joined Joseph to add a further 78 for the fourth wicket, a partnership that put the Windies on course for victory.
But Hinds, attempting to sweep leg-spinner Malinga Bandara, was caught at mid-wicket and Narsingh Deonarine, after having scored 21 from 31 balls in a stand of 47 with Joseph for the fifth wicket, was run out, leaving the Windies in trouble at 195 for five.
His dismissal triggered a slide, with two further wickets - Omari Banks and Joseph.
It left the lower order with too much to do and though Browne belted two fours and two sixes, Windies A fell short.
Perera finished with four for 38 while Amarasinghe claimed three for 33.Earlier, Sri Lanka got an unbeaten 82 from Russell Arnold as they reached their eventual total after losing the toss and being asked to bat. Kaushal Lokuarachchi slammed 47 from 66 balls while Avishka Gunawardene weighed in with 38 from 36 balls.
Gunawardene and Mahela Udawatte, who scored 26, posted 51 for the first wicket to give Sri Lanka a healthy start.
Fast bowler Gavin Tonge was Windies A's best bowler with three for 46 while Ravi Rampaul finished with two for 35.
