Morales homered twice off the Bristol native — a solo home run in the first and a three-run shot in the fifth — and tied a career high with six RBIs to lead the Seattle Mariners to a 9-2 win over the Rangers on Tuesday night.
Grimm (7-6) gave up six runs and seven hits in four innings. He was chased in favor of Ross Wolf after Morales hit his second homer.
The 24-year-old Grimm gave up a career-high three home runs and has a 9.31 ERA over his last six starts.
“When talking about youth on the mound, you’re going to get inconsistency,” Texas manager Ron Washington said. “We have to get past the inconsistency.”
Grimm retired the first two batters of the game before Raul Ibanez lined a 2-1 pitch over the fence in right field. Three pitches later, Morales followed with a solo drive to make it 2-0.
The switch-hitting Morales, who has been hampered by a sore back, hit .235 with one home run in 25 June games before jumping on the Rangers for the 10th multihomer game of his career. Seattle’s designated hitter added a two-run single in the sixth.
“Their big bats in the order didn’t miss,” Washington said.
Seattle had 13 hits and scored its most runs since beating San Diego 9-0 on May 27.
Joe Saunders (6-8) won for the first time in eight regular-season starts at Rangers Ballpark. The left-hander allowed two runs — one earned — and struck out five in 6 2-3 innings.
Saunders, who won the 2012 AL wild-card game at Rangers Ballpark with Baltimore, came in 0-7 with a 9.91 ERA in the regular season at Texas.