COLOMBO: New Zealand rode on a swashbuckling opening stand between Brendon McCullum and Jesse Ryder to hammer 170-4 in the second Twenty20 match against Sri Lanka on Friday.

The pair put on 84 in 10.2 overs after New Zealand captain Daniel Vettori won a second successive toss and elected to bat under lights at the Premadasa stadium here.

Left-handed Ryder smashed three sixes and as many fours in his 52 off 37 balls, while McCullum hit a 34-ball 49 with two sixes and four boundaries.

Martin Guptill and Jacob Oram further boosted the total with a 43-run stand for the fourth wicket in 27 balls, before Guptill was bowled by Lasith Malinga off the final ball of the innings.

Sri Lanka, World Twenty20 finalists in June, must score almost nine runs an over to draw the two-match series after New Zealand won Wednesday's opening game by three runs.

McCullum and Ryder bulldozed the Sri Lankan attack for the first 10 overs, racing to 83 runs without being separated.

The pair took 19 runs in Malinga's second over as McCullum slashed a six over point and drove the next ball through the covers for a boundary.

Veteran Sanath Jayasuriya broke the stand in the 11th over when he beat McCullum in the air and the batsman offered a simple return catch.

Ryder took over after McCullum's departure, striking two sixes and a boundary in the 12th over sent down by Tillakaratne Dilshan which yielded 20 runs.

Sri Lanka hit back with two quick wickets as Ryder was caught in the covers off Ajantha Mendis and Ross Taylor (16) was trapped leg-before by Jayasuriya.

Jayasuriya finished with 2-22 and Mendis took 1-21, while pace spearhead Nuwan Kulasekara went for 40 runs in four wicketless overs.