The Australia midfielder was a mammoth presence as Australia bowed out of Russia on a high after a stirring 1-1 draw against a fortuitous Chile.
And he believes Ange Postecoglou's men will take that momentum to Saitama, with a point and three more at home to Thailand five days later all that is required to clinch a return trip to Russia in 2018.
One of six changes against the South American champions in June, Luongo believes the performance that night in Moscow showed "a different side" to the national team, as finesse gave way to fight and ferocity.
"I felt like we showed the boss a different aspect to our game," said Luongo. "That fighting type of play can be useful in a certain types of games.
"We were proper fighters that day. I think everybody will be on a bit of a high from the Confeds Cup.
"We know how much is at stake against Japan, but I can't see the boss trying to set up just to go for a point. I think we will go there on the front foot."
After surprising Australia with their cautious approach during the 1-1 draw with the Socceroos in Melbourne last October, Luongo is expecting the Samurai Blue to show more of a cutting edge in what is virtually a must-win match for them.
Though they head Group B by a point from Saudi Arabia and Australia, their final group game is away to the Saudis, leaving little margin for error.
"We didn't expect them to sit back so much against us. Maybe they were a bit scared and worried about us and decided to change their approach," he mused.
"They're at home now and I think they might come out and play, which would suit us. It will be more the Japan we know.
"It's a lot easier when teams come out and try to play their game against us. I think we have the ability to open them up and expose them.
"Ange has picked a very experienced squad. And there are a lot of options in every position, which might give him a little bit of a headache selection wise.
"Looking at the games left I would rather have our two matches than theirs. The pressure is just as much on them as it is on us."
Luongo was one of the big success stories against Chile, in the absence of Tom Rogic and Aaron Mooy, with Tim Cahill and James Troisi also in commanding form, in a further reminder of the depth available to Postecoglou.
"I have a little bit of confidence and I've taken that with me into the start of the new season with QPR," he said.
Speaking in the wake of the London club's 2-1 loss at Cardiff City on Sunday (AEST), Luongo continued: "I found my feet a bit in that game against Chile and figured out a few things I can do to get myself into matches.
"It's was different ... it was a real battle. We more than held our own, although on paper we were missing a lot of our main players."
Luongo highlighted the impact of veteran talisman Cahill that night, and his enduring importance to the cause.
"Playing with James Troisi in one of those number 10 slots, Tim really added something different," he said.
"I thought he was amazing ... that fighting spirit he possesses picked us up, got everybody going and created a spark.
"It's handy to have a player like that. He just keeps surprising people with the way he moves and plays. I think he's got a few years left in him yet."