Japan overpowered a dogged United States 34-20 to win the Pacific Nations Cup in Suva on Saturday and enjoy a timely confidence boost six weeks out from hosting the World Cup.
Captain Michael Leitch scored a try in each half, with winger Kenki Fukuoka and fullback Ryohei Yamanaka also crossing to give the undefeated Brave Blossoms their third triumph in the tournament after claiming the 2011 title and sharing the 2014 trophy with Samoa.
It was the United States' first defeat of the tournament after thrashing Canada in Colorado and edging Samoa last weekend.
Despite a selection shake-up and some early fumbles, Japan soon produced the high-pace, running rugby that saw them rack up big scores in the defeats of Fiji and Tonga.
Jamie Joseph, back in charge after missing the win over Tonga due to the death of his mother, was underwhelmed by the win, however, and felt his team had put themselves under pressure.
"I thought the players didn't play our best rugby tonight but we did play a couple of good tests," Joseph said. "I thought we played well against Fiji and then they sort of followed on last week (against Tonga). It was difficult, the U.S. made it really difficult for us today.
"I just think it's our first goal, our first goal was to win the PNC ... The next goal is to go to the World Cup and play our Japanese brand of rugby and make the top eight."
Joseph would nonetheless have been pleased with the form of rugby sevens specialist Fukuoka and Yamanaka, each of whom shredded the Eagles' defence with a number of jinking runs.
Fukuoka was unlikely not to have a hat-trick of tries, having fumbled an early chance and later been denied another when his foot grazed the touch-line after he beat two defenders and retrieved his own kick behind the goal-line.
Japan enjoyed the perfect start, with Leitch rumbling over at the back of a line-out drive in the fourth minute and Fukuoka grabbed a second try in the opening quarter. Flyhalf Flyhalf Yu Tamura sandwiched the conversions with a penalty as the Brave Blossoms stormed to a 17-0 lead.
The U.S. finally steadied through winger Madison Hughes who crossed after a brilliant carry and offload from flyhalf AJ MacGinty. Fullback Will Hooley put the Eagles back within seven points with a penalty on the half-hour mark.
Japan were stalled for a period by some stout U.S. defending and a slew of handling errors when deep in attack, with Fukuoka blowing a certain try with a fumble on the goal-line as he sprinted to chase down a grubber kick.
Held to 20-13 at halftime, Joseph's team knuckled down after the break and were rewarded with a try to Yamanaka, who received a clever inside pass from Tamura at the end of a period of sustained pressure.
Leitch completed a stunning team try 15 minutes into the second period, grabbing an off-load on the goal-line from Shota Horie after a brilliant dash down the left wing by Yamanaka.
The U.S. fought it out to the finish, however, and their forward pack wheeled round the Japan scrum deep in attack to set up a late try to flanker Hanco Germishuys.
"I'm still happy that we're on song for our World Cup preparation," U.S. coach Gary Gold said. "I'm really proud of our guys for how hard they stuck in and fought right to the end and I think we're in a good place. It's been a good couple of weeks."