Red Sox rookie Daniel Nava was called up from Triple-A Pawtucket and hit a grand slam on the first major-league pitch he faced on Saturday afternoon.
Nava connected with a fastball from Philadelphia's Joe Blanton in the second inning.
"It's ridiculous," he said after Boston's 10-2 win.
Only four players in big league history have hit grand slams in their first at-bat.
Boston's Nava Hits GS On First Pitch Faced