Daniel James Nava is an American former professional baseball outfielder. He played in Major League Baseball (MLB) for the Boston Red Sox, Tampa Bay Rays, Los Angeles Angels, Kansas City Royals, and Philadelphia Phillies. Nava is only the fourth player in MLB history to hit a grand slam in his first major league at bat and the second to do it on the first pitch.

In baseball, a grand slam is a home run hit with all three bases occupied by baserunners, thereby scoring four runs—the most possible in one play. According to The Dickson Baseball Dictionary, the term originated in the card game of contract bridge, in which a grand slam involves taking all the possible tricks. The word slam, by itself, usually is connected with a loud sound, particularly of a door being closed with excess force; thus, slamming the door on one's opponent(s), in addition to the bat slamming the ball into a home run.