"It's good, when a pitcher makes a mistake, to capitalize on it," Nixon said, "and I was fortunate enough to hit a couple of mistakes."
Oakland's fielding mistakes may have been worse than its pitching problems. Nine of Boston's runs were unearned -- all five in the fourth inning and four in a seven-run seventh -- and first baseman Scott Hatteberg made two errors on one play in the fourth.
"If we make that play, perhaps we get out of that inning with no runs," Athletics manager Ken Macha said. "It was a big play of the game."
Oakland's problems started in the first when Dan Haren's first pitch to Ramirez, a breaking ball, hit the slugger on the left side of the head. There were no symptoms of a concussion and Ramirez was resting comfortably at home, team spokesman Glenn Geffner said. There was no estimate on when he might play again.
Those woes continued when Macha was ejected by plate umpire Mark Carlson in the sixth after the first pitch to Jason Kendall was called a strike. And Oakland's hitters stranded 12 runners.
"It would be worse if we got nobody on," Macha said.
"It didn't unravel me," Haren said of the beaning. "It was the only curveball I threw that went that way."
Tim Wakefield (4-1) got his 118th win with the Red Sox, moving into sole possession of fifth place in team history, one ahead of Pedro Martinez and Smokey Joe Wood. Boston's starters are 8-0 in 10 games since Curt Schilling and David Wells went on the disabled list.
"I didn't have my best knuckleball," said Wakefield, who allowed three runs and seven hits in six innings with five walks and two strikeouts. "I was very fortunate that out offense scored as many runs as it did."
Johnny Damon went 2-for-4, extending his hitting streak to 15 games and raising his batting average to .373. Only Detroit's Carlos Guillen at .387 is better in the AL.
"If I didn't get my job done, I know I have other guys on the team who will pick me up," Damon said. "That let us relax."
Wakefield left after six innings with a 6-3 lead, and Boston batted around in the seventh when shortstop Mario Scutaro booted a grounder for an error. Keeichi Yabu allowed all seven runs, including the homers to Nixon and Millar, who ended the longest home run drought of his career at 120 at-bats.
When Millar first returned to the dugout, his teammates ignored him.
"I got back, and no one got up," he said. "I said, 'That's OK, I don't deserve it.' "
Haren (1-5) pitched 4 2/3 scoreless innings for St. Louis in last year's World Series against Boston. But on Monday the Red Sox loaded the bases with no outs in the five-run fourth on singles by Ortiz, Millar and Edgar Renteria. Bill Mueller then grounded to Hatteberg, who dropped the ball, allowing Ortiz to score. When Hatteberg threw wildly to first base for his second error on the play, Millar also scored.
Renteria scored on a wild pitch before Nixon's double made it 6-2. Scutaro doubled in a run for Oakland in the sixth.
Oakland, which had been shut out in its previous two games by the New York Yankees, went ahead 2-1 in the third on a two-run double by Bobby Kielty.
- Oakland was 4-for-12 with runners in scoring position after going 4-for-37 in those situations in the previous four games.
- The University of Massachusetts' new basketball coach, Travis Ford, threw out the ceremonial first pitch. He was a point guard at Kentucky and coached at Eastern Kentucky.
- Ramirez was hit in the thigh by Seattle's Joel Pineiro in the opener of a doubleheader on Sunday. He stayed in until Payton pinch hit for him in the fourth. In the second game, Ramirez struck out as a pinch hitter for the last out.