The 32-year-old slugger hit a dramatic three-run homer in his first game back with the BayStars since 2019, leading Yokohama past the Swallows.
The BayStars' 5-3 win over the Hanshin Tigers also means the Yomiuri Giants are eliminated from postseason contention for the second year in a row.
A consistently good hitter since making his NPB debut in 2013, Toshiro Miyazaki leads the Central League with a .362 batting average.
The 28-year-old veteran struck out nine batters and issued only one walk.