Mitch Garver of the Rangers celebrates after scoring on a double by Robbie Grossman during the fourth inning against the Boston Red Sox on Tuesday in Boston. Michael Dwyer/Associated Press

BOSTON — Mitch Garver hit a three-run homer, Dane Dunning pitched six solid innings and the AL West-leading Texas Rangers had a rain-delayed 6-2 victory over the Boston Red Sox on Tuesday.

Robbie Grossman and Josh Jung each added an RBI double for the Rangers, who won for just the second time in six games. Garver also had a bases-loaded walk.

“Dane, he’s been good all year,” Rangers Manager Bruce Bochy said. “I don’t know what else to say about him.”

Jarren Duran had a triple and double, and Justin Turner an RBI single for Boston, which had its three-game winning streak halted.

The game was delayed for 1 hour, 47 minutes.

With a light rain falling early in the game and turning heavier in the middle innings until the umpires called for the tarp with the Red Sox batting in the eighth, the 28-year-old Dunning (8-1) kept Boston’s offense in check, giving up a run and six hits with four strikeouts and a walk.

“Going into the season, I was just more or less trying for a starting spot, but obviously things just didn’t work out,” said Dunning, who lowered his ERA to 2.61 after moving into the rotation when Jacob deGrom was lost for the season and needed surgery for a torn ulnar collateral ligament in his right elbow.

Garver’s homer into the center-field bleachers off reliever Kaleb Ort (1-2) moved the Rangers ahead 3-1 in the second following singles by Nathaniel Lowe and Ezequiel Duran.

“I saw Jarren (Duran) out there running and he backed off like it was going to hit the wall,” Garver said of his shot. “With two runners on, I can’t pass the runner on first. I was kind of just coasting.”

Will Smith got Alex Verdugo to pop out with two runners on for the final out, recording his 15th save.

Boston had moved in front when Duran tripled into the triangle in center and scored on Verdugo’s grounder to short.

“It was four runs in six innings,” Red Sox Manager Alex Cora said of his team using an opener. “That’s the way we look at it. … It just happened that today we got a lot of hits and didn’t score many runs.”

• Former Red Sox and current Rangers pitcher Nathan Eovaldi caught a ceremonial first pitch from Boston bullpen catcher Mani Martinez, who recently became a U.S. citizen.