Brandon Belt became the first player in Giants history (that's 139 years) to hit a first-inning grand slam while batting in one of the top three spots in the lineup.
The Giants franchise has been around since 1883 and had played 21,149 games coming into Tuesday night's doubleheader in Colorado (20,940 regular season and 209 postseason).
A Twitter commenter reported that Von Hayes of the Phillies hit a first-inning grand slam as a leadoff hitter on June 11, 1985, against Calvin Schiraldi and the Mets. Hayes had begun the bottom of the first with a solo dong.