Sri Lanka deafeated Afghanistan by 42 runs at Pallekele International Cricket Stadium to go 1-0 up in the three-match series.
Afghanistan skipper Hashmatullah Shahidi won the toss and invited Sri Lanka to bat first.
The hosts posted 381 for 3, thanks to Pathum Nissanka's 210 not out.
The unstoppable Nissanka's knock included 20 fours and eight sixes from the 139 balls he faced in his first ODI since the World Cup. In reply, Afghanistan were restricted to 339 for 6 in 50 overs.
