Eldridge went 1-for-4 with a walk, a grand slam and a second run scored in Wednesday's 11-10 win over the Nationals.
Per Maria Guardado of MLB.com, the 21-year-old slugger's blast put him in the record books as the youngest player in history to hit a walk-off grand slam, breaking a mark that had been held by Hall of Famer Roberto Clemente since 1956. Eldridge has caught fire and bashed his way into an everyday role over the last couple weeks, slashing .426/.500/.766 across his last 13 games with seven doubles, three homers, 10 RBI and 15 runs.