Semien’s homer, a two-run drive into the left field bullpen, broke a tie with Davey Johnson (1973 for Atlanta), and gave Toronto an early lead in their September showdown against an AL wild-card rival.
Rogers Hornsby (42 home runs in 1922) and Brian Dozier (42 in 2016) are the only other second basemen in big league history to reach the 40-homer mark.
Semien’s homer was Toronto’s ML-leading 249th of the season.
Four of Semien’s home runs this season have come while he was playing shortstop. But the nine-year veteran, an All-Star for the first time this season, has made 142 of his 157 starts at second base.
Semien signed a one-year, $18 million contract with Toronto this season. He finished third in AL MVP voting in 2019 with Oakland, when he hit 33 homers with 92 RBIs with an .892 OPS, and is in line to be one of the most marketable free agents this offseason.
The 31-year-old Semien had played most of his career at shortstop before leaving the A’s to join the Blue Jays.
The Associated Press contributed to this report.