Defensive coach Mark McCall had earlier demanded a positive approach from his side and Munster team-mates David Wallace and Frankie Sheahan bulldozed their way through for Ireland's openers inside the first eight minutes.

The hosts remained in the contest thanks to two turnover tries for Daisuke Ohata either side of the interval kept the home side interested, but five Irish tries in the latter stages of the game, including two for Harlequins ace Gavin Duffy and Sheahan's second, sealed the win .

Some good work from Munster wing Anthony Horgan sent Wallace over for Ireland's first score on three minutes.

Humphreys converted, and in doing so took Ronan O'Gara's title as leading Irish points-scorer.

He then added the extras to Sheahan's second try of the tour, which was set up by a clever inside pass from Peter Stringer five minutes later.

Japan responded well and they closed the deficit to 14-10 by half-time.

The Cherry Blossum's flyhalf Keiji Hirose slotted a 32nd-minute penalty before winger Ohata capitalised on an Ireland turnover to race away to score.

Three tries in the opening nine minutes of the second period saw the visitors take control of the game once again.

Humphreys notched the first two minutes in, after some quick thinking from replacement Alan Quinlan. Duffy added Ireland's fourth less than a minute later and full-back Girvan Dempsey grabbed the third on 49 minutes.

Duffy added his second eight minutes later to increase their lead to 40-13.

Ohata then claimed his second of the afternoon, and incredibly his 46th try in 46 Tests, but Ireland had the final say when hooker Sheahan dived over for his second following a close-in drive.