Japan boosted their hopes of winning Olympic gold in baseball by fending off fellow contenders Cuba 6-3.
Matsuzaka pitched almost the entire game
Starting pitcher Daisuke Matsuzaka threw confidently deep into the ninth innings to take the win.
And Japan added three home runs, the first coming when Kazuhiro Wada drilled over the left fence scoring two runs.
Kenji Jojima and Norihiro Nakamura had back-to-back solo blasts in the
fourth innings and the Cubans were unable to claw their way back.
"This win feels great," said pitcher Nakamura.
"It may only be the preliminary round, but Cuba is the team you want to beat.
"In Sydney, we lost and that spurred some bad memories," he added.