Cespedes beat Cincinnati's Todd Frazier, 9-1, in the final round to win the Home Run Derby for the second straight year.
The A's slugger became the first back-to-back winner since Griffey captured the 1998 and '99 crowns for the Seattle Mariners.
Incredibly, both competitors barely made it out of the first round, advancing on swing-offs. Frazier downed former Twins player Justin Morneau, 1-0, while Cespedes topped A's teammate Josh Donaldson, 2-1.
Frazier belted six homers over the fence in the second round to a pair for Colorado's Troy Tulowitzki, the captain of the National League Home Run Derby team.
Cespedes cranked out nine homers to three for Baltimore's Adam Jones in the AL's second round.
Frazier made it to the final despite hitting one home run in the National League's last round. Miami's Giancarlo Stanton received a bye after belting six homers in the first round, including a 422-foot upper deck shot to left that nearly escaped Target Field. Stanton, though, was blanked in his next attempt.
In the AL final, Cespedes smashed seven homers to four for Toronto's Jose Bautista, who hit 10 homers in the first round. Bautista, though, had to wait nearly two hours before taking another swing by facing Cespedes in the AL's final round.
Cespedes went first in the title round when the skies opened up and raindrops started again at Target Field. Cespedes' seventh homer was a 452-foot titanic blast.
A's third-base coach Mike Gallego, who pitched to Cespedes last year at New York's Citi Field, delivered the home run balls Monday night. Last year, Cespedes hit 32 homers, two more than the 2014 competition.
Frazier's brother Charlie, a sixth round draft pick of the Marlins, never made it to the majors, although he did serve as Todd's pitcher Monday.