TAIPEI (Kyodo) -- Hiroto Saiki threw 5-2/3 scoreless innings as defending champion Japan beat Taiwan 3-1 to take sole possession of the Group B lead at the Premier12 baseball tournament Saturday.

Japan improved its record to 3-0 and dropped Taiwan to 2-1 in six-team, round-robin play. The top two Group B finishers will meet the top two from Mexico's Group A -- Venezuela and the United States -- in the Super Round from Thursday at Tokyo Dome.

Saiki allowed just three hits, all singles, while striking out five and walking two at Taipei Dome.

"The cheering at this stadium was way more than I expected," the Hanshin Tigers right-hander said. "We scored three runs in the early innings, so I was able to relax and enjoy the atmosphere while on the mound. It was a good experience."

The young Samurai Japan team took a quick 1-0 lead in the top of the first when Masayuki Kuwahara, who reached on an error leading off the game, scored on a Shota Morishita sacrifice fly.

A run-scoring double from Ryosuke Tatsumi in the third and a solo home run by Sosuke Genda in the fourth pushed Japan's lead to 3-0 before Dai Pei-fong got Taiwan on the board with a seventh-inning blast.

Taiwan's starting pitcher, Chen Po-ching, was charged with three runs, two earned, in 3-1/3 innings.

Earlier in the day, Cuba edged Australia 4-3, leaving both teams with 1-2 records.

Japan will face Cuba on Sunday and the Dominican Republic on Monday. The final and third-place games will be played Nov. 24 at Tokyo Dome.