ARLINGTON, Texas (AP) – Boston’s Bill Mueller became the first player in major league history to hit grand slams from both sides of the plate in a game, connecting for three homers to lead the Red Sox over the Texas Rangers 14-7 Tuesday night.

Mueller, batting left-handed, hit a solo homer in the third inning against R.A. Dickey.

Batting right-handed, he hit his first slam off Aaron Fultz in the seventh for a 9-4 lead. One inning later, he connected from the left side against Jay Powell for a 14-4 advantage.

“You never come to the ballpark thinking you’re going to do anything like this,” Mueller said. “I’m just trying to have some good at-bats, and I guess some of my good at-bats went over the wall tonight.”

Mueller had a career-high nine RBIs with the first three-homer game of his career. He has 13 homers this season, also a career best, and four career slams.

It was the 12th time a player hit two grand slams in a game, the first since Boston’s Nomar Garciaparra against Seattle on May 10, 1999.

“I’m very humbled by it. It was just one of those nights that went in my favor and kept going. Maybe someday I’ll really appreciate it. … I feel good. I’m ready to go them tomorrow.”

Mueller had his second multihomer game of the season, the third of his career. He hit two homers against the New York Yankees on July 4, connecting from each side of the plate.

Boston, which began the night 11/2 games behind the first-place New York Yankees in the AL East, won for the eight time in 10 games.

Garciaparra and Trot Nixon also homered for the Red Sox.

Texas led 4-2 lead in the seventh when odd Walker singled off Erasmo Ramirez, and Rosman Garcia (1-1) walked Garciaparra.

Gabe Kapler ended an 0-for-18 slide with an RBI single, and David Ortiz hit a two-run double that put Boston ahead 5-4.

Garcia failed to retire any of the four batters he faced, allowing four runs, two hits and two walks.

Boston starter Tim Wakefield (8-5) had trouble locating his knuckleball, and Doug Mirabelli had four passed balls, two short of the AL record set by the Rangers’ Geno Petralli in 1987.

Wakefield allowed four runs and six hits in six innings, struck out eight and walked two.

Dickey, trying for his first victory as a starter, allowed two runs and seven hits in five innings. He struck out a career-high six and walked one in his third career start.

Notes: Boston acquired right-handed reliever Scott Williamson from the Cincinnati Reds for minor league left-hander Phil Dumatrait, a minor leaguer to be named and cash. … It was 97 degrees when the game began. … Kapler replaced Manny Ramirez in left field in the fifth. Ramirez has been bothered by a sore left quadriceps and fell awkwardly when he went back and fell while trying for Diaz’s double in the fourth. Ramirez is day to day.

AP-ES-07-29-03 2349EDT