Boston improved to 7-1 on a nine-game homestand and will go for a three-game sweep of the Dodgers when Clay Buchholz faces Hiroki Kuroda on Sunday night.
Ramirez homered in his second game back at Fenway Park against his former team, a sixth-inning solo shot off knuckleballer Tim Wakefield. The enigmatic slugger also had his first stolen base since 2008.
Victor Martinez had a two-run homer and Kevin Youkilis a solo shot for the Red Sox, who committed four errors.
Wakefield made his 200th career start at Fenway, tying Roger Clemens for the most in club history.
Bill Hall opened the ninth with a single against reliever Ronald Belisario (1-1), but was cut down at second on Daniel Nava's attempted sacrifice. One out later, Marco Scutaro walked before Pedroia singled to right on a 1-2 pitch from Jonathan Broxton.
Nava slid in headfirst at home plate, easily beating the throw from Andre Ethier.
Jonathan Papelbon (2-3) worked a scoreless ninth for the win.
The Dodgers scored a pair of runs to tie it 4-all in the seventh. Garret Anderson doubled and scored on Blake DeWitt's double to right. DeWitt advanced to third when Hall misplayed a carom for his second error of the game. Manny Delcarmen relieved Wakefield, and Matt Kemp tied it with a sacrifice fly.
Martinez's two-run homer on a 3-0 pitch from starter Vicente Padilla put Boston ahead 3-1 in the fourth.
Ramirez homered into the second row of Green Monster seats to cut it to 3-2 in the sixth. As he rounded the bases, he was serenaded with a mixed response of cheers and boos — much like most of his first game back on Friday night.
Youkilis' drive went out of the ballpark, over the Monster seats to make it 4-2 in the sixth.
Ramirez singled, stole second and scored on Anderson's single, giving the Dodgers a 1-0 lead in the second. Boston tied it on Nava's RBI double in the bottom half.
Wakefield gave up four runs — three earned — and five hits in 6 1-3 innings. He walked two and struck out six.
Padilla made his first start since going on the disabled list April 23 with an inflamed nerve in his right arm. He gave up four runs and five hits in 5 1/3 innings.
Notes
Red Sox OF Mike Cameron, who missed time with abdominal strain, was given the day off. … Padilla fanned David Ortiz on a 95-mph fastball in the third and threw him a 54-mph curve in the sixth. … Dodgers reliever Hong Chih-Kuo has retired all 22 left-handed hitters he's faced this season, striking out 11. … Ramirez was 6-for-26 against Wakefield with no homers before Saturday. … Former Dodgers manager Tommy Lasorda was at the game. … Wakefield remained 0-4 at Fenway Park this season. … Dodgers 1B James Loney made a nice grab of a foul pop, leaning over and into a photographers' pit.