Moustakas blasted a pair of homers, added a two-run single and knocked in nine as the Royals posted a 14-6 win in Baltimore on Saturday, Sept. 12.
The 27-year old singled in the sixth to tie the game at 4-4.
One inning later with the Royals on top 7-4, he banged a grand slam. He capped his night with a three-run homer in the ninth.
This season, Moustakas has 18 homers with 71 RBI and a .282 batting average.
Bumgarner raised his record to 18-7 and lowered his ERA to 2.91, after an 8-0 one-hit victory at home over the San Diego Padres on Saturday, Sept. 12.
The 26-year old lost his bid for a perfect game when Melvin Upton singled with two out in the eighth inning. He finished with nine strikeouts and threw 111 pitches.