Joe Carter also accomplished the feat with Cleveland in 1987, when he had 32 homers and 31 steals. Sizemore is the first American League player to join the 30-30 club since Alfonso Soriano did it for Texas in 2005.
Sizemore, who began the day with 34 stolen bases, led off Monday night's game and hit the second pitch from Detroit's Armando Galarraga into the visitors' bullpen at Comerica Park to become the first 30-30 player in the majors this season.
The three-time All-Star added his 31st home run leading off the third inning. It was his fifth multihomer game of the year.
With more than a month left in the season, Sizemore has a chance to become the fifth major league player to reach the 40-40 plateau. Jose Canseco (1988), Barry Bonds (1996), Alex Rodriguez (1998) and Soriano (2006) are the only ones to do it.