"It was good I was able to complete four innings," said Darvish who had been struggling in exhibition game appearances prior to the start of the Classic. "My out pitch was working well tonight."
Japan threatened to score in the first two innings, but China starter Li Chenhao worked out of a couple of jams and stranded three Japanese base runners.
The Samurai broke the scoreless deadlock in the bottom of the third when Norichika Aoki singled to center, driving in Hiroyuki Nakajima, who had walked and stole second. Murata followed with his line-drive home run into the left-field stands to make the score 3-0.
Japan added a fourth run without a hit in the bottom of the sixth inning when with two outs after two walks and a force out, China pitcher Sun Guoqiang balked with runners at first and third.
Superstar and fan favorite Ichiro Suzuki was held in check by the Chinese hurlers, going 0-for-5. Like Darvish, Ichiro also slumped through the Classic tuneup games.
Japan manager Tatsunori Hara said the key to the game was the pitching by Darvish. "He set the stage, and I am very proud of him," said Hara. "When you don't give the other team any runs, that is a shortcut to victory."
China manager Terry Collins also expressed pride in the way his team -- especially the pitchers -- performed.
"Whenever you face a lineup like (Japan's) and give up only five hits, you've pitched a good game."
As for his team's handling of Ichiro, Collins said, "We got him at the right time. You're not going to hold down Ichiro for very long, and he could have just as easily gone 5-for-5.
The atmosphere at Tokyo Dome resembled that of a mid-summer all-star game with a lavish opening ceremony, the first ball thrown by Sadaharu Oh, the world home run king and manager of Japan's 2006 Classic championship team, and numerous pitching changes because of the Classic pitch-count rule.
Japan's Crown Prince Hironomiya and Crown Princess Masako attended the game, waving to the crowd from a royal box at the end of the seventh inning.
Japan now faces the winner of Friday's game between Korea and Chinese Taipei on Saturday night, while China plays the loser of that game on Saturday afternoon.
Starting pitchers for Friday's game have been announced as Ryu Hyunjin for Korea and Lee Chen-Chang for Chinese Taipei.