Kusal Mendis hit a gritty 74 not out as Sri Lanka posted a thrilling three-wicket win against New Zealand to clinch the three-match one-day international series on Sunday.

Sri Lanka were reeling at 93-5 but Mendis played the anchor role to perfection despite battling a groin injury to hand the hosts their fifth ODI series triumph this year.

It was also Sri Lanka's first win in an ODI series over the Black Caps in 12 years.

Mendis was ably supported by Maheesh Theekshana who hit an unbeaten 27 off 44 balls as Sri Lanka reached the target of 210 runs with six balls to spare.

The day-night match was reduced to 47-overs a side because of rain interruptions.

The third and final ODI will also take place at Pallekele on Tuesday.

"The injury is not too serious, but I struggled with shot making," said Mendis.

"My getaway shot is the sweep, but I couldn't sweep tonight and it was tough."

Off-spinner Michael Bracewell was the most successful Kiwi bowler, picking up a career-best four wickets for 36 runs off his 10 overs.

Mendis, fresh off a century in the first ODI, led the chase with his composed 102-ball knock, studded with six boundaries.

At one stage, Sri Lanka were tottering on 163 for seven but an unbroken 47-run partnership for the eighth wicket between Mendis and Theekshana saw them through.

- Kiwi batting woes -

"It is always a challenge when you are defending a low score. Kusal played well," said Kiwi skipper Mitchell Santner.

"If we had put a few more runs on the board and got 240, it would have been a different story. We have done well with the ball, but the problem is with batting."

Earlier, spinners Jeffrey Vandersay and Theekshana shared six wickets to help bowl out New Zealand for 209 in 45.1 overs.

Mark Chapman hit a sparkling 76 off 81 balls and shared 75 runs for the fifth wicket with Mitchell Hay who fell one run short of his maiden one-day half-century.

Their batting was the lone bright spot for the Kiwis who struggled to get going against Sri Lankan spinners.

Left-arm spinner Dunith Wellalage set the tone in the second over, clean-bowling opener Tim Robinson with a sharp delivery.

But Chapman opened up to hit seven boundaries and three sixes in his defiant innings.

His spirited effort ended when Avishka Fernando took a spectacular diving catch inches off the ground.

Sri Lanka's fielding, though not flawless, had its moments of brilliance.

While there were dropped catches and lapses in the field, Avishka Fernando stood out with three stunning catches.

Another highlight came from Pathum Nissanka, who sprinted in from long-on to claim an extraordinary catch, sending Santner (six) back after the left-hander failed to pick Vandersay's googly.