BALTIMORE -- Ryan Mountcastle homered twice and tied a team record with nine RBIs, helping the Baltimore Orioles rally from a four-run deficit to a 12-8 victory over the Oakland Athletics on Tuesday night.

Mountcastle hit a three-run homer in the fifth inning and added a grand slam in the seventh as the Orioles overcame a difficult home debut for right-hander Grayson Rodriguez. Austin Hays homered and had four hits for Baltimore, which handed the A's their sixth straight loss.

Mountcastle tied the franchise's single-game mark for RBIs set by Jim Gentile in 1961 and matched by Eddie Murray in 1985.

"Two greats," Mountcastle said. "To tie them in, I guess, any category is super special. Pretty cool night."

Mountcastle became the first player anywhere in the majors to drive in nine runs since Adam Duvall in 2020.

According to ESPN Stats & Information data, Mountcastle is the third player in MLB this season to hit a three-run homer and grand slam in the same game, joining Dodgers duo Trayce Thompson and Max Muncy. He's the first Orioles player to pull off the feat since Ramon Hernandez against the Mariners in 2006.

Rodriguez allowed six hits and four walks in 4⅓ innings, although he also struck out six. The Baltimore right-hander -- one of baseball's top-ranked pitching prospects -- allowed single runs in the first and third, and after he departed with the bases loaded in the fifth, all of those runners came in to score.

Mountcastle hit a sacrifice fly in the first and an RBI single in the third.

The Associated Press contributed to this report.