Tonga claimed their first win of the 2011 World Cup with an entertaining but controversial 31-18 victory over Japan in Whangarei on Wednesday.

Two refereeing blunders both benefitted and hurt Japan, with the initial error helping them come back into the match through a try from Kensuke Hatakeyama that looked like a clear double movement.

Three yellow cards were also issued in the match - to James Arlidge, Halani Aulika and Tukulua Lokotui - as Tonga snapped a five-match losing streak against the Pacific Nations Cup champions.

Tonga's physicality won a tight battle over the athleticism of John Kirwan's Japan side, who are stuck at the bottom of Pool C while Tonga moved to third.

After being forced to defend their line for the opening six minutes, Japan finally conceded the opening points of the match through a try from number eight Viliami Ma'afu, who had been denied moments earlier.

Tries were awarded to both sides in quick succession, two to Japan and one to Tonga. But the try to Japanese prop Hatakeyama - which was referred upstairs by referee Dave Pearson - looked like a clear double movement.

The tendency for Japan to concede points immediately after posting some of their own meant Tonga were able to re-establish a small lead thanks to the boot of Kurt Morath.

They extended that lead to eight points thanks to Arlidge's contentious yellow card penalty, and despite Shaun Webb reducing the lead back to five by half-time, a third penalty to Morath saw Tonga maintain that advantage with 30 minutes to play.

The Pacific Island side rubbed further salt into the wound when substitute Fetu'u Vainikolo dotted down in the corner to extend Tonga's lead to 15 points as the final quarter approached.

But just as Tonga looked to be coasting, Halani Aulika was yellow carded for a similar offside offence to Arlidge in the first half.

Japan made it count when centre Alisi Tupuailei darted through the defence to score an important try for the Asian champions.

But as they had done earlier, they conceded three points moments after scoring, meaning they had a 31-18 deficit to overcome with 12 minutes to go.

With time ticking on, Japan's focus shifted from a win to securing a bonus point. But even a yellow card to Lokotui with two minutes to play could not help the Brave Blossoms.