The Junior All Blacks capped their unbeaten Pacific Nations Cup campaign by scoring seven second half tries to rout Japan 51-3 in Tokyo on Sunday.

The New Zealand team, who had already won the six-nation tournament heading into this weekend's final round, ran in a competition-high eight tries against the last-placed Japanese.

Seven of them came in the second spell after they struggled to forge a 10-3 halftime advantage at the Prince Chichibu Memorial Ground.

In Sunday's other game, popular Samoan rugby veteran Brian Lima said farewell to his home crowd in winning style as his side thrashed Tonga 50-3 in Apia.

It was the last home game for the 34-year-old stalwart of Samoan rugby, who has announced he will step down from Test rugby following the World Cup in France later this year.

The victory confirmed Samoa as the leading island nation in the Cup, finishing third behind regional powers the Junior All Blacks, who won the series for the second consecutive year, and Australia A, who drew 14-14 with Fiji on Saturday.

Samoa were never in danger against Tonga, running in seven tries and leading 29-3 at the turn.

In Japan, the John Kirwan-coached Japan held firm through the first 30 minutes, matching the visitors in every facet to lead 3-0 courtesy of a penalty to first five-eighth Eiji Ando.

However, the sinbinning of Japan's New Zealand-born flanker Glen Marsh kick-started the Junior All Blacks' point-a-minute romp from that point.

Five-eighth Stephen Brett landed a penalty and then converted a try to prop Wyatt Crocket three minutes later, a sweeping effort that mirrored much of the play in the second-half.

Reserve pivot Stephen Donald bagged two tries in the closing seven minutes while Brett, centres Tane Tuipulotu and Ma'a Nonu and wingers Anthony Tuitavake and Rudi Wulf all crossed once as the backs hogged the second-half tries.

Tuitavake was the most potent runner, while loose forwards Sione Lauaki and Jerome Kaino made regular inroads after the initial Japanese fire was snuffed out.

New Zealand's average score through their five games was 46-7 and they scored 32 tries to four.

The Junior All Blacks team featured eight starting changes from the side who hammered Australia A 50-0 in Dunedin last weekend, a match which ensured New Zealand would defend their title.

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