Panasonic Wild Knights completed the league and cup double on Sunday when they beat Toshiba Brave Lupus 30-21 in the final of the All-Japan Championship.

In the last domestic rugby game played at National Stadium before it is demolished to make way for a new arena that will make its debut at Rugby World Cup 2019, the Wild Knights once again owed their victory to a superb defensive effort and their world-class half back pairing of Berrick Barnes and Fumiaki Tanaka.

Top League MVP Barnes picked up an injury before the game but brushed it aside to once again control the game and land his kicks when they counted, finishing the day with three conversions and three penalty goals from as many attempts.

"He tweaked his groin in the warmup, so to put in a performance like that under duress was outstanding," Panasonic assistant coach Phil Mooney said of the Australian.

Tanaka, who had made the most of a Super Rugby bye for the Highlanders this weekend to fly back for the final, showed just why he is so highly rated in New Zealand, constantly sniping around the edges of the breakdown and putting in some huge hits that resulted in penalties for his team.

"Fumi allows us to up the tempo when we are on the front foot and he made some key defensive plays," said Mooney.

To its credit, Toshiba made the final a much closer affair than many had anticipated. The last meeting between the two sides — in the Top League playoffs — had seen Panasonic win 55-15, but this was a pumped-up Toshiba side led superbly by Michael Leitch, who showed he has returned to form following a horrendous run of injuries.

Despite playing with 14 players for 10 minutes following the sin binning of Steven Bates as early as the sixth minute and a serious looking injury to center Taiki Watanabe six minutes later, Toshiba more than held its own.

"It's hard to be too disappointed as we almost pulled off a massive upset for the second week running," said Bates. "I am very proud of our efforts and thought we put on a good show."

However, as most sides have discovered this year, Panasonic is not only one of the most skilful sides in Japanese rugby, it is also the fittest. And true to form, Toshiba saw the game run away from it the longer it went on.

"In the last 15 minutes we were trying to keep the ball, but we had a couple of turnovers and a couple of scrums went against us," said Leitch.

Played under perfect conditions in the nation's capital, Toshiba had led 14-10 at the break thanks to tries by Shuhei Oshima and Yuta Mochizuki, both of which were converted by Takahiro Ogawa, against one by Akihito Yamada for Panasonic.

But the Wild Knights came out firing in the second half, and a good break and offload by Barnes saw Yasuki Hayashi cross six minutes after play resumed.

Barnes added the extras and a penalty before his vision and left boot set up JP Pietersen for a try in the 61st minute.

Taking a ball going backwards, the Wallaby pivot realized the Wild Knights had players out wide and his improvised kick was pounced on by the South African World Cup winner. Barnes' conversion saw Panasonic go 27-14 up.

A superb try from Leitch straight from the kickoff gave Toshiba some hope, but Barnes put aside his sore groin to land a penalty from 48 meters in the 74th minute to ensure the Wild Knights their first national championship under the Panasonic brand, their first three coming when they played in red as Sanyo.

"That was a great final," said Mooney. "It was everything you expected it to be. It was very physical, and Toshiba had us under a lot of pressure. But the trust the players have in each other and the knowledge of the game plan allowed us to finish strongly."