ARLINGTON -- This is what you call sudden impact.

That’s what newly acquired infielder Derek Dietrich was hoping to deliver, and he did just that Wednesday night in his first game with the Rangers. Dietrich had three hits, including an eighth-inning single that started a game-winning, five-run rally, and Texas pulled out a stunning 7-4 victory over Seattle at Globe Life Field.

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“I want to have an impact and help this team win in any way,” Dietrich said. “That was fun. I was pumped up. I don’t know if it was the crowd noise or the clamoring in the dugout, but it felt good to feel that again. It’s been a little bit [of time] for me.”

The Rangers won two out of three games against the Mariners to complete a 5-1 homestand. They are 8-9 this season and currently sit in second place in the American League West, four games behind the A's and a half-game ahead of the Astros. (The top two teams from each division will make the expanded 16-team postseason this year.)

“That’s a huge victory for so many reasons,” manager Chris Woodward said. “Especially the way we won that game. We know it is not going to be easy offensively. We haven’t hit as well as we would like, but we’ve managed to win some games by doing small ball, stealing bases, getting big hits. Those are the things we have to do to win the tough games.”

Dietrich, an eight-year veteran, signed with Texas on Monday. He started at second base because Woodward wanted to give Rougned Odor a mental break. The Rangers were attracted by Dietrich’s versatility and left-handed bat, but also his energy, which was on display Wednesday night.

“We've had a ton of energy, obviously, before we got him,” Woodward said. “I feel like we've done a good job, especially in the dugout, but he just adds a little bit more to that. It just never quits, and that's just kind of his mentality. That's what we want on our ballclub.”

The Mariners scored four runs off Rangers starter Jordan Lyles in the second inning, and it stayed 4-0 until the sixth. The Rangers scored an unearned run that inning and another run in the seventh, when Shin-Soo Choo walked, stole second and scored on a single by Willie Calhoun.

That set up the rally in the eighth, which Dietrich started with a one-out single off right-hander Erik Swanson. Elvis Andrus, hitless on the night and batting .156 at that point, then doubled to left field, putting runners on second and third.

“I’m sure if you ask him, it was a big sigh of relief,” Woodward said. “Elvis looked better today. His posture was better. Everything about his swing, I felt, looked better today, looked more comfortable. He wasn’t out in front, he wasn’t chasing pitches. I’m really happy for him, and I’m sure he’s really excited about it.”

Todd Frazier, who was given the night off, then went up to pinch-hit for Rob Refsnyder, and he was hit by a pitch to load the bases.

That brought up No. 9 hitter Jeff Mathis, and the Rangers had both Odor and Robinson Chirinos on the bench. But Chirinos has a sore left ankle, and Texas was without a backup catcher. So, Woodward stayed with Mathis, who hit a broken-bat flare into left for a single to bring home Dietrich and cut the Mariners' lead to 4-3.

Choo hit a sacrifice fly to right that brought home Andrus and tied the game at 4, then Swanson hit Isiah Kiner-Falefa with a pitch to load the bases.

Mariners manager Scott Servais brought in right-hander Taylor Williams to face Calhoun. But Williams let go a wild pitch, allowing Frazier to score the go-ahead run. Calhoun followed with a two-run single to left to push the Rangers' lead to 7-4 and cap the rally.

The five-run frame equaled Texas' largest offensive output in an inning this season.

“That was nice being able to fight and come back, put together some good at-bats,” Calhoun said. “That has been our motto -- just pass the baton to the next guy. It is pretty nice to be able to do that. Obviously, this ballpark plays differently, so we can’t rely on the long ball as much as we did in the past. Overall, that’s going to make us better hitters.”