Rodriguez hit his 684th career home run leading off the sixth inning Tuesday night, lifting New York into a 1-1 tie with Baltimore and chasing Orioles starter Kevin Gausman. The Yankees eventually fell 2-1.
Rodriguez, 40, hadn't hit the 30-homer mark since 2010. He didn't play last year while serving a season-long drug suspension.
Aaron held the career home run record of 755 before it was broken by Barry Bonds, who finished with 762.
The homer was A-Rod's fourth in five games and boosted his career hit total to 3,056, moving him past Rickey Henderson for 22nd in major league history.
The Associated Press contributed to this report.