Arlington, Texas — Scott Feldman, starting after Roy Oswalt was scratched with back tightness, threw seven strong innings to lead the Texas Rangers to a 9-1 victory over the Boston Red Sox on Monday night.

Feldman (4-6) won his fourth straight decision and pitched his longest outing since throwing eight innings on June 2, 2010. He gave up one earned run and seven hits with five strikeouts.

Just before the game started, it was learned Texas starting pitcher Colby Lewis will miss the rest of the season because of a torn flexor tendon in his right elbow that will require surgery. Martin Perez, who was called up on Monday after Lewis was placed on the disabled list, will start today’s game against the Red Sox, but he would have been available out of the bullpen if Feldman had faltered early.

In three games against Boston this season, the Rangers have outscored the Red Sox 33-7.

Ian Kinsler went 3-for-4 and Craig Gentry went 2-for-4 with an RBI for Texas. Josh Hamilton and Mike Napoli both had two RBIs in the Rangers’ first home game since July 8.

Boston’s only run came on a home run by Jarrod Saltalamacchia in the second inning. Saltalamacchia’s 19th home run of the season sailed 422 feet to right-center field with two outs.

The Red Sox, who have lost 12 of 18, left eight base runners on base.

In the third, Texas scored three earned runs against Boston starter Felix Doubront (10-5). Gentry singled and Kinsler walked, then a double steal put the two at second and third. Elvis Andrus run-scoring singled to stretch his hitting streak to 11 games. Dustin Pedroia overthrew first base to let Kinsler score. Hamilton drove in a run with a double and Michael Young’s one-out single scored Hamilton to make it 4-1.

In the sixth, Napoli hit his third home run in as many games, a two-run shot that traveled 416 feet to left field that made it 6-1. That hit knocked out Doubront, who pitched five innings and gave up six earned runs and eight hits.

Frankin Morales relieved Doubront and gave up three-straight hits to Brandon Snyder (double), Gentry and Kinsler. Gentry’s single drove in Snyder, and Gentry scored on an error by Boston left fielder Carl Crawford after Kinsler’s single. Hamilton hit a sacrifice fly for a 9-1 lead.

Note: Red Sox manager Bobby Valentine said the team could skip struggling LHP Jon Lester’s start this weekend against the Yankees. “Maybe that’s something he needs,” Valentine said. “He’s going to throw here Wednesday. With the off day Thursday he could get a little extra rest.” Lester (5-8, 5.46) has lost his last three starts, giving up 21 earned runs in 12 1/3 innings. He allowed a career-worst 11 earned runs in four innings of Sunday’s 15-7 loss to Toronto.