"Some games we haven't played to our potential," Manager Mike Scioscia said before the game.
"Some of the games they've just come out here and beat us. They've taken it to us last year and this year."
And again Saturday, when the Red Sox won, 5-0, in front of 40,025 at Angel Stadium.
"No matter whether we're 0-19 against Boston, as long as we win the division, that's all I care about," outfielder Torii Hunter said.
The Red Sox cruised to their seventh victory in eight games behind a brilliant performance by right-hander Daisuke Matsuzaka, who gave up one hit and struck out nine batters in eight innings.
"His fastball was explosive today," Hunter said.
Matsuzaka (2-2) was sharp in his previous start too, throwing seven scoreless innings to beat Toronto on Monday.
"I pitched the same way in my last [start]," Matsuzaka said through an interpreter. "I'm bringing the same mentality and I executed with the same technique."
Boston's starters have given up no more than two earned runs in each of the team's last eight games.
"Those guys, they're pitching well, but we have to do a better job against good pitching and we haven't been able to do it this series," Scioscia said.
It marks a season-high four-game winning streak for Boston, which began the season by dropping 10 of 12 games.
The Angels have lost three games in a row after winning 11 of 14 games.
Right-hander Ervin Santana, who was seeking his first win since Sept. 21, gave up five earned runs and nine hits in seven innings.
Santana (0-3) struck out nine batters, but the Angels gave him zero offense to combat an early deficit, Boston leading, 2-0, by the third inning on run-scoring singles by Carl Crawford and Adrian Gonzalez.
And in the fifth inning, third baseman Kevin Youkilis, who sat out Friday's game because of a leg injury, hit a 93-mph fastball over the right-field wall for a two-run home run.
"It was supposed to be inside and it was right down the middle," Santana said of the pitch.
Crawford doubled in the sixth inning and scored on a double by Jason Varitek, his first run batted in this season, to make it 5-0.
By then, the Angels' offense consisted of a single by third baseman Alberto Callaspo in the second inning, their only hit until Erick Aybar singled in the ninth.
The Angels are batting .150 (15 for 100) through three games of the four-game series, which ends Sunday.