According to ELIAS

Kepler, Max walkoff 061216Max Kepler‘s first career home run–a 10th-inning three-run blast over the centerfield wall and off the batters-eye at Target Field gave the Twins a dramatic 7-4 win over the Boston Red Sox yesterday afternoon. Among the 138 players in major-league history to hit 300 career home runs, only two had their first one come as a walkoff shot in extra innings: Miguel Cabrera (in his major-league debut) and Alfonso Soriano.

Congratulations Max!