ARLINGTON, Texas -- Kendrys Morales busted out of his power drought in a big way.
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.
"He lost his stroke there a little bit," Mariners manager Eric Wedge said. "I think it's because he has been trying to do too much. But he's a good hitter who can do a lot of damage."
Morales had a solo home run in the first and a three-run shot in the fifth off rookie Justin Grimm. Seattle's designated hitter added a two-run single in the sixth to help the Mariners win for the first time at Texas this season.
"I worked in the cage the last three or four days to make adjustments to feel more comfortable," Morales said through a translator. "I want to take an aggressive approach every time. That's what it takes to be a winner."
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.
Raul Ibanez, who hit 10 homers in June, had a solo shot for his 20th of the season as the Mariners opened a six-game road trip.
The Mariners had 13 hits and scored their most runs since beating San Diego 9-0 on May 27.
"I think the whole team swung the bats well," Ibanez said. "Even the outs that were made were good swings. It was a good collective effort."
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 Ibanez lined a 2-1 pitch over the fence in the right. Three pitches later, Morales followed with a solo drive to make it 2-0.
"Their big bats in the order didn't miss," Washington said.
Texas' Leonys Martin dropped down a bunt single leading off the third to extend his hitting streak to 15 games, the longest active run in the majors. Martin scored two batters later on Elvis Andrus' single.
After Dustin Ackley had a run-scoring double in the fourth to push the lead to 3-1, the Mariners scored three runs in the fifth.
Nick Franklin led off with a single and Ibanez reached on Ian Kinsler's error at second base to set the stage for Morales. He hit the first pitch from Grimm into the seats in right, extending Seattle's lead to 6-1.
It was Morales' first multihomer game since last Aug. 8 against Oakland.
Morales, who went 3 for 5, capped his big game with a two-run single in the sixth to make it 8-1. It was the fourth time he had six RBI in a game. He last drove in six on July 30, 2012, against Texas.
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. The left-hander was coming off his shortest start of the season when he allowed six runs in 1 2/3 innings June 25 against Pittsburgh.
"This place has torn me up a few times," Saunders said. "Everybody knows they can hit the ball. I wanted to work down in the zone and try to get ahead, something I haven't been doing, and throw strikes."
Saunders got double-play grounders to end the fifth and sixth. After he recorded the first two outs of the seventh, Andrus and Nelson Cruz had consecutive singles to chase Saunders.
Texas RHP Colby Lewis (elbow) threw 37 pitches in the bullpen and is expected to have another bullpen session Thursday. ... Rangers opening-day starter Matt Harrison, out since April while recovering from back surgery, threw from 120 feet. ... Ackley was back in the starting lineup after missing Sunday's game with a sprained left thumb. ... Texas DH Lance Berkman (sore right knee) missed his fourth straight game. Berkman said he hopes to return to the lineup Wednesday night. ... Rangers radio announcer Eric Nadel missed most of the game because of laryngitis. Texas' lead radio voice called the first inning before leaving. ... The Rangers outscored the Mariners 23-3 in a three-game sweep April 19-21.