The oldest winning pitcher in Nippon Professional Baseball history, Masahiro Yamamoto, continued to impress in the minors on Thursday as he builds a case for a chance to pitch on the first team.

Yamamoto, who will turn 50 on Aug. 11, allowed a run on seven hits in six innings to earn the win in the Chunichi Dragons' Western League game against Orix in Kobe. Working in his seventh farm game of the season, the lefty touched 133 kph in a six-pitch outing.

"It was hot but I was able to pitch," said Yamamoto, who was the Dragons' fifth-round draft pick out of high school in 1983 and has a career 219-165 record with the Central League club.

"My condition is a lot better than it was last year before I was called up," he said.

Last September, Yamamoto rewrote NPB's record as the oldest winning pitcher, surpassing the mark set by Hall of Famer Shinji Hamazaki in 1950, when he won as a reliever at the age of 48 years, four months. The major league record for the oldest pitcher to win a game was set in 2012 by 49-year-old lefty Jamie Moyer.

Yamamoto, who did not allow a run in either of his previous starts, changed speeds well to keep the Buffaloes off the board until he surrendered back-to-back doubles in the fifth, when he was able to escape further damage.

"I'm competing for a chance to pitch on the first team. All I can do is get results," Yamamoto said.