Five days after scattering eight hits over six shutout innings against the Yankees, the rookie right-hander was just as hittable for the White Sox, who blasted Tazawa for nine runs on 10 hits over four frames in the Red Sox's 9-5 loss at Fenway Park.
J.D. Drew hit a pair of home runs for Boston (73-54), which found itself trailing, 9-0, through 4 1/2 innings of a game that included a mop-up pitching performance from Nick Green.
"They came out and swung the bats well," Kevin Youkilis said. "They put us in a position where it was going to be tough to come back. We didn't give up, but it was just one of those games."
Coupled with the Rangers' 7-2 win over the Yankees on Thursday afternoon, the setback trimmed the Red Sox's lead in the American League Wild Card race to 1 1/2 games.
The fourth start of Tazawa's Major League career was easily his worst, as he exited after 85 pitches.
"He obviously wasn't commanding any of his secondary stuff," manager Terry Francona said. "They were looking for that fastball, and when you're throwing one pitch, you better be pretty fine with it.
"It was a tough night from the beginning, and we didn't have a lot of protection for him."
The White Sox had plenty of protection for John Danks, who scattered six hits and struck out six over six innings of two-run ball to pick up his 12th victory.
After a second-inning sacrifice fly by Mark Kotsay put Chicago on top, Jayson Nix lifted a fly ball to left that clanked off the top of the scoreboard for a two-run double. Scott Podsednik then cracked an RBI single up the middle to score Nix.
Jim Thome opened the White Sox third-inning four-spot with a sacrifice fly of his own, and Carlos Quentin walloped a curveball from Tazawa over the Green Monster one batter later for a two-run shot. Nix chipped in again with an RBI single later in the frame.
Chicago (64-64) capped its scoring binge off Tazawa (2-3) in the fourth, when Thome laced a line drive past the outstretched glove of Drew in right for an RBI double.
"He was falling behind in the count," Victor Martinez said of Tazawa. "And when he threw strikes, they weren't missing."
Boston's offense finally awoke in the fifth, as Drew wrapped a Danks offering around Pesky's Pole in right. Alex Gonzalez followed suit with a towering shot over the Monster for his second tater in as many nights.
Following a collision at home plate to conclude the fifth, Jacoby Ellsbury was removed from the game with what the club termed a mild left ankle sprain.
"He got hit in the shin guard," Francona said. "I don't think it's anything serious. We'll certainly check it in the morning."
On came Green to pitch the eighth, as he retired the side while working around a two-out walk to Paul Konerko. The utility infielder then tossed a scoreless ninth to cap an effort that was very much appreciated by Francona.
"That's not an easy decision," Francona said. "Early in the game, as bleak as the game was looking, it looked worse from where we were."
Eighth-inning RBI doubles from David Ortiz and Jason Bay trimmed the White Sox's lead to 9-4, and Drew went deep again in the ninth.
Though their comeback proved to be too little too late, the Red Sox took pride in fighting until the last out.
"In the little time that I've been here, I see the faces of my teammates, and they don't quit," said Martinez, who was acquired from the Indians on July 31. "We're going to keep playing hard until the end. This game is 27 outs, and you just never know what's going to happen."
John Barone is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.