Stellar pitching from starter Masato Morishita and relievers keep the Americans off the scoreboard
Ryoji Kuribayashi holds the U.S. in the 10th to pick up the win.
Japan will face the U.S. on Monday for a chance to reach the semifinals.
That Yamamoto started the first of two tuneup games is a fairly strong indication that Inaba plans to have him start the opening game on Wednesday.
Manager Atsunori Inaba’s team features a mix of veteran standouts and rising stars, including Orix Buffaloes hurler Yoshinobu Yamamoto.
In his first regular-season appearance with the Eagles since 2013, Tanaka pitches five innings and allows three runs and four hits.