After the first match ended in a 17-17 draw in Kitakyushu, it took a very late penalty from McKenzie Hawkins to separate USA from Japan in this weekend's rematch in Shizuoka, the Women's Eagles claiming a hard-fought 11-8 victory and a 1-0 series win at the Shizuoka Stadium Ecopa.
Hawkins' fellow vice-captain and hooker Kathryn Treder had got the tourists on the scoreboard early on with a try after just seven minutes. However, it was Japan who went into half-time with the lead following a try from Seino Saito and Ayasa Otsuka's penalty.
Hawkins drew USA level six minutes after the restart with her first successful kick at goal and the score remained at 8-8 with a second consecutive draw appearing likely until the fly-half held her nerve to send the ball through the poles with a few minutes remaining, just as she had done a week earlier to snatch the draw in Kitakyushu.
USA have climbed two places to seventh in the World Rugby Women's Rankings as a result of the win, regaining the places they lost after the draw, with Wales and Italy the teams to slip one place. Japan remain in 11th place.