The USA picked up their first win over Japan since 2003 with a 23-18 success in Sacramento in the Pacific Nations Cup.
After going down to Samoa in their first game of the tournament, the Eagles were able to turn things around against Japan, who had rested a number of key individuals.
Andrew Durutalo scored the Americans' only try, with fly-half AJ MacGinty chipping in with six penalties as his team came from 18-9 down to record the win.
Japan managed two tries through Akihito Yamada and Ryu Koliniasi Holani, but it wasn't enough, with Michael Broadhurst's late yellow card ending their chances of stealing the win.
With the two teams set to meet again in the pool stages of the World Cup, this was the opportunity to strike a psychological blow, but Eddie Jones instead chose to test out his depth by resting a number of first team regulars.
That seemed to affect the Japanese discipline, and they were punished by three MacGinty penalties in the first half. Harumichi Tatekawa responded with two for Japan, and they crossed for the first try on the stroke of half-time.
After a break from impressive full-back Yoshikazu Fujita took the Brave Blossoms into the American 22, Yamada popped up in support to race over.
Tatekawa missed the conversion, but his team led 11-9 at the break. They continued in the same vein at the start of the second half, with Takudzwa Ngwenya sin-binned for an intentional knock-on four minutes in.
With an extra man, Japan were able to open up the Eagles for a second time, with Holani going over off the back of a powerful scrum. Tatekawa converted on this occasion, and at 18-9, Japan looked to be in control.
The Americans responded however, with three more penalties from MacGinty to draw the scores level at 18-18 with quarter of an hour remaining.
Durutalo then went over after a powerful rolling maul, the Eagles using their strong lineout to good effect.
MacGinty missed the conversion but the USA were able to hold on for the win despite late pressure from Japan, with Broadhurst binned in the dying stages for a reckless tackle at a breakdown.
The two teams could yet meet again in the third place play-off depending on results next week, with the USA hosting Tonga, while Japan take on Fiji.
Pens: MacGinty 6
Yellow Card: Ngwenya
Tries: Yamada, Holani
Pens: Tatekawa 2
Yellow Card: Broadhurst
USA: 15 Chris Wyles (c), 14 Blaine Scully, 13 Seamus Kelly, 12 Thretton Palamo, 11 Taku Ngwenya, 10 AJ MacGinty, 9 Mike Petri, 8 Danny Barrett, 7 Andrew Durutalo, 6 Scott Lavalla, 5 Cam Dolan, 4 Hayden Smith, 3 Titi Lamositele, 2 Zach Fenoglio, 1 Eric Fry.
Replacements: 16 Phil Thiel, 17 Nick Wallace, 18 Chris Baumann, 19 Louis Stanfill, 20 Alastair McFarland, 21 Shalom Suniula, 22 Folau Niua, 23 Zach Test.
Japan: 15 Yoshikazu Fujita, 14 Karne Hesketh, 13 Kotaro Matshushima, 12 Ryohei Yamanaka, 11 Akihito Yamada, 10 Harumichi Tatekawa, 9 Keisuke Uchida, 8 Ryu Koliniasi Holani, 7 Michael Broadhurst, 6 Justin Ives, 5 Luke Thompson, 4 Hitoshi Ono, 3 Kensuke Hatakeyama, 2 Takeshi Kizu, 1 Keita Inagaki.
Replacements: 16 Hisateru Hirashima, 17 Hiroki Yuhara, 18 Shinnosuke Kakinaga, 19 Kazuhiko Usami, 20 Tsuyoshi Murata, 21 Atsushi Hiwasa, 22 Kosei Ono, 23 Tim Bennetts.
Venue: Bonney Field, Sacramento, California
Referee: Luke Pearce (England)