Jarrod Dyson, Ketel Marte and David Peralta began the game with three consecutive home runs. Eduardo Escobar and Ildemaro Vargas each hit two home runs, and Alex Avila hit his fourth home run of the year for the Diamondbacks.
Arizona finished with a club-record eight home runs.
"You can't really explain it," Diamondbacks manager Torey Lovullo said. "It was just a bunch of really good hitters getting after it and not letting up on the gas pedal."
Hoskins' ninth-inning home run tied the record at 12. Bruce made history two batters later.
"It felt like every ball that went in the air was a home run," said Kingery, who has six home runs this season. "I'm not sure if that had to do with the weather, the humidity, I don't know. It was just crazy out there."
The previous Major League record of 12 home runs in one game was held by the Chicago White Sox and Detroit Tigers. The two teams accomplished the feat on May 26, 1995, at Tiger Stadium, and again on July 2, 2002, at Guaranteed Rate Field in Chicago.