Updated

Pitching on a season-high 14 days of rest, the Rangers' Scott Feldman filled in admirably for Roy Oswalt.

With the news earlier Monday that Opening Day starter Colby Lewis will miss the rest of the season due to a torn tendon in his right elbow, Feldman may not have to wait another 14 days to make his next appearance.

Feldman tossed seven innings of one-run ball and Ian Kinsler tallied three hits and two runs scored as Texas routed the Boston Red Sox, 9-1, in the opener of a three-game set.

With Oswalt's achy back flaring up on him, Feldman (4-6) made the spot- start and fanned five while scattering seven hits. The 29-year-old hadn't pitched since July 8 when he earned a win with two scoreless innings of relief in a 4-3, 13-inning Texas triumph over the Minnesota Twins.

"Tremendous outing," Rangers manager Ron Washington said. "We certainly needed him to give us a chance tonight and he went way beyond what we expected."

Oswalt received a cortisone shot in his lower back Monday and is expected to make his next start.

Josh Hamilton provided an RBI double and a sacrifice fly, while Craig Gentry racked up two hits, two runs scored and an RBI for the Rangers, who had lost three of their last four coming in.

Felix Doubront (10-5) was charged with six runs on eight hits and three walks over five-plus frames for Boston, which has dropped four straight.

"We got to go out there and battle," Red Sox catcher Jarrod Saltalammachia said. "We got to pitch better, we have to play better."

Saltalamacchia recorded his 19th homer of the year -- which leads all MLB catchers -- to open the scoring in the second, but the Rangers took the lead following a four-run third.

Gentry led off with an infield single and after Kinsler walked, a double steal put runners on second and third with none out. They both crossed the plate on Elvis Andrus' infield single and Dustin Pedroia's throwing error.

On the play, Andrus rolled one back up the middle. Pedroia ranged far to his right and made a fine backhanded stab, but threw the ball away to first while making an off-balance throw.

Up next, Hamilton brought Andrus home with a double down the left-field line, and Michael Young's single to left-center allowed Hamilton to score and make it 4-1.

Texas blew the game open with a five-run sixth.

Mike Napoli smacked a two-run blast to left, Gentry and Kinsler registered RBI singles and Hamilton lifted a sacrifice fly to left, making it a 9-1 game.

Game Notes

The Rangers moved to 32-12 this season when Hamilton picks up an RBI...Coming into the game, left-handed starters were 4-0 with a 1.83 ERA against Texas...The Rangers are 22-10 against Boston since the start of 2009.