Japan beat South Korea -- minus Son Heung-min -- 3-0 on Thursday to claim bragging rights in the first football friendly between the two rivals in 10 years.
Miki Yamane scored on his debut to give Japan the lead in the 17th minute, before Daichi Kamada added a second 10 minutes later and Wataru Endo notched a late third.
Tottenham Hotspur forward Son was pulled from Korea's squad and did not travel to Japan, after club boss Jose Mourinho complained that the player was called up while injured.
Japan's Takumi Minamino started the match despite Southampton manager Ralph Hasenhuttl protesting that it was "nonsense" for his player to travel for international duty during the pandemic.
"Of course there are things that we can learn from this result and analyse, but the circumstances were not the same for the two teams," said South Korea manager Paulo Bento.
The result gave Japan a win in their first home game since November 2019, and a decent workout before they resume their World Cup qualifying campaign against Mongolia on Tuesday.
"To be honest, before the game it had been a while since we last played and there were maybe some nerves," said Kamada.
"The players who were coming from Europe were a bit heavy in training and that was true for me too. I wondered if it was going to be alright but as soon as the game started, we flicked the switch and everyone played well."
The game between the 2002 World Cup co-hosts was played in near-total silence amid coronavirus restrictions, with the 8,300 fans in the cavernous Nissan Stadium banned from cheering.
But that didn't stop Japan from flying out the blocks, with full-back Yamane latching onto Yuya Osako's back-heeled flick to smash home the opener with less than 20 minutes gone.
Eintracht Frankfurt striker Kamada then doubled Japan's lead in the 27th minute, striding forward with the ball before lashing it past Korean goalkeeper Jo Hyeon-woo.
And Endo made it three in the 83rd minute, rising highest at a corner to plant home a header and seal a resounding win for Japan.
"People have had a lot of restrictions on their lives and some people were wondering whether we should be playing a game at a time like this," said Japan manager Hajime Moriyasu.
"I understand why people feel that way but I hope when they see the players working hard and giving their all, they see that sport can make a contribution."