"See, you can't keep ripping our bullpen," manager Joe Torre said with a touch of sarcasm. "This is a huge win for us. We needed a close game to win. We needed a number of people to do a job, and they did."
The slump had owner George Steinbrenner seething in Florida and it raised questions about Torre's job security. But the Yankees (9-13) got what they needed -- a well-pitched game, even though they lost yet another starter to injury.
"Hopefully, today will be the day that we turn it around," Jason Giambi said.
Karstens, hit by Julio Lugo's line drive on his first pitch, has a broken right leg. He won't need surgery and is expected to return this season, team physician Dr. Stuart Hershon said.
"We're lucky it didn't hit pure bone," Torre said. "It could've been much worse."
Swept at Fenway Park last weekend, New York improved to 1-4 this year against its longtime rival and can win the series Sunday with ace Chien-Ming Wang on the mound. Julian Tavarez pitches for the Red Sox.
Rivera, who entered with an uncharacteristic 12.15 ERA in eight appearances, worked a scoreless ninth for his first save in three chances. One of his blown saves came in the series opener at Fenway.
"Today was different. The ball was moving from the first pitch," Rivera said.
Igawa (2-1) left with two on in the seventh to a standing ovation from the sellout crowd of 55,026. The Yankees spent $46 million to bring him over from Japan in the offseason, but the left-hander was skipped in the rotation this weekend after flopping in his most recent start Monday night at Tampa Bay. He was sent to the bullpen to work on his mechanics with pitching coach Ron Guidry.
"When he made the effort the other day to throw in the 'pen, there was a different look in his eye," Guidry said. "This game right here is big for him. I was very proud of the way that he pitched today."
Brian Bruney came on and got three quick outs to preserve New York's three-run lead. Kyle Farnsworth gave up a two-out RBI single to Mike Lowell in the eighth before getting Coco Crisp on a called third strike.
Crisp slammed his bat and helmet to the ground and was immediately ejected by plate umpire Bruce Froemming.
"I would have been frustrated, too," Boston manager Terry Francona said. "Did you see the pitch? Tough, tough."
Rivera allowed a leadoff single to pinch-hitter Jason Varitek in the ninth before retiring Alex Cora, Julio Lugo (on a fine play by third baseman Alex Rodriguez) and Kevin Youkilis. That left David Ortiz on deck when the game ended.
"He became tenacious, and you weren't going to take this from him," Torre said about Rivera. "I just think he hasn't been out there enough."
Derek Jeter had three hits for the second consecutive game, but the Yankees left 12 runners on base. Boston stranded 10.
Karstens (cracked fibula) was hit in the right knee by Lugo's line drive and crumpled to the turf in pain. He tried to stay in and threw five more pitches -- two for strikes. But the rookie was lifted after Youkilis' single and limped off the mound.
"We've had a lot of stuff happen," general manager Brian Cashman said. "You couldn't print what was going through my head, or what was coming out of my mouth."
Karstens began the season on the disabled list with tendinitis in his right elbow. He was roughed up by the Red Sox for seven runs and nine hits in 4 1/3 innings last Saturday, his first outing of the year.
Wearing sunglasses on a cloudy afternoon and working exclusively from the stretch, Igawa yielded only two hits and four walks. He struck out six and received hearty pats on the back from several teammates when he departed.
"I have better control of the ball when I pitch from the stretch," Igawa said through a translator.
He also got Ortiz to ground into two double plays, the first one on his second pitch.
"He was all right. Nothing special," Ortiz said. "He was throwing a lot of hittable pitches, but we were just not hitting it."
Hideki Matsui drew a one-out walk in the fourth and Posada homered into the right-field upper deck, New York's first extra-base hit in 24 innings.
Melky Cabrera blooped an RBI double to left in the sixth, chasing Wakefield.
- Bothered by an aching back, Johnny Damon was the DH for the Yankees. Cabrera started in CF.
- Lowell, a Gold Glove winner in 2005 with Florida, made two errors at 3B. He has eight this season.