Yoenis Cespedes and Brandon Moss hit consecutive home runs off the Texas Rangers' starting pitcher in the third inning and the Oakland Athletics snapped their AL West rivals' four-game winning streak with a 5-1 victory Monday night.
Grimm (2-3) lost his third straight despite receiving an extra day of rest between outings. He gave way to Joseph Ortiz after plunking Daric Barton to begin the sixth.
"April was a lot more fun, especially between starts when things are going well," said Grimm, called up from Triple-A Round Rock on April 11. "I have to keep my head up and keep working through it. I have to stay mentally strong when things aren't going well."
Cespedes hit an 0-1 pitch just over the center-field wall above a leaping Leonys Martin. Moss connected for his sixth home run with a drive to nearly the same spot as Cespedes moments before.
Moss' homer was the 7,000th in Oakland history. Hall of Famer Reggie Jackson hit the first on April 10, 1968.
Grimm, who got a no-decision and a pair of wins before his current three-game skid, failed to make it past the fifth inning for the second straight game. The former Virginia High star allowed seven hits and gave up five runs, all earned. He struck out three and walked two.
Oakland produced the first multihomer game against Grimm in six starts.
A's starter A.J. Griffin (4-3) matched his season high with eight strikeouts. He went seven innings and didn't walk a batter for the first time this season.
Griffin faced either the minimum or one more batter in each of his final five innings, helped by a pair of double plays.
"It's the best start command-wise I've had in the pros, in the major leagues," he said.