BOSTON -- At this point, CC Sabathia's career doesn't require much in the way of validation. But one area of his 2011 resume did need a little touch-up work.

For the first time in his career, Sabathia had lost four games in a single season to the same team. That was unlikely enough coming from the left-hander, but the underlying problem was that he was pitching for the Yankees and the team that had beaten him four times was the Red Sox. Ouch.

Sabathia's work this season could be divided into two categories. When opposing anybody but the Red Sox, he was 17-3 with a 2.40 ERA; Cy Young Award territory. But against Boston, he was 0-4 with a 7.20 ERA.

This had to change, not only for Sabathia's status as an elite pitcher, but for the Yankees' own chances in the American League East and beyond, in a possible AL Championship Series matchup against Boston. The Yankees have had a fine season, overcoming injuries to important personnel, developing more pitching depth than many thought possible, boasting a lineup that includes both impressive power and speed. But again, they had the one highly visible drawback -- a 2-10 record against the Red Sox.

On Tuesday night at Fenway Park, Sabathia got on the board against the Yankees, four starts later than he would have liked, but finally and definitely. His performance was labor intensive, but it was effective. Sabathia worked six innings and gave up two runs in a 5-2 Yankees victory. He had to throw 128 pitches to get through those six innings, but it was worth the effort.

Did he have to win this start against the Red Sox?

"Of course," Sabathia told a group of reporters with a smile. "So you guys stop talking about it."

At this point, a victory over the Red Sox had become a necessity for the Yankees, in particular a victory by the ace of their rotation.

"I think it means a lot," Yankee manager Joe Girardi said of Sabathia's victory. "It's a huge game, a huge series."

So the Yankees moved within a half-game of first place in the AL East. For Sabathia, it was a strange statistical performance -- 10 strikeouts, 10 hits allowed, 10 Boston runners left on base during his six innings.

The Yankees fully expected a bounce-back performance from Sabathia against Boston. As Girardi put it before the game when asked about Sabathia's 0-4 mark against the Sox:

"CC is the kind of a guy who would take it as a challenge and learn from it. I don't think CC is the kind of guy who would say, 'They've got my number.'"

The Red Sox did not have Sabathia's number, but they did not exactly go quietly, either. The 128 pitches Sabathia had to throw represented his highest pitch count of the season. His previous high this year -- 119 pitches -- came in a seven-inning outing against Detroit on May 3 in which he took the loss.

"They have a great lineup," Sabathia said of the Red Sox. "They take a lot of pitches, they foul a lot of pitches off. When you make mistakes, they make you pay.

"They had a lot of runners on base, but we were able to make pitches when we needed to."

Girardi said he wanted to get six innings out of Sabathia, because he was somewhat short in the bullpen. The high pitch count was not a particular concern.

"CC's done it before," Girardi said. "CC's strong. And he's had extra rest."

When Sabathia was asked if the high pitch count might bother him later, he responded: "I don't think so. I've had a lot of rest for the last month. I felt good [in the sixth inning]. I felt like I had a lot left in the tank."

With the victory, his 18th of the season, Sabathia became the second Yankees pitcher to win 18 or more games in his first three seasons with the team. For perspective on how much starting pitching has changed, the only other Yankees hurler to accomplish that feat was Jack Chesbro, in the first decade of the last century. Chesbro won 21, 41, 19 and 23 games for the Yankees in his first four seasons with them, at the dawn of this franchise, 1903-06. He started 167 games over those four seasons and completed 129 wins. Then again, Chesbro, who was 30 when he won 41 games, never won a game in the Majors after 1908.

Sabathia has had far easier starts than the one he had against Boston on Tuesday night. But this may have been very high on the list of games that he and his team absolutely needed to win. The Red Sox made him work every pitch of the way, but when he needed an out, he found one the vast majority of the time.

Sabathia struck out Adrian Gonzalez three times, and that just won't happen for most pitchers. At times, this looked like an effort of sheer will for CC Sabathia. But it was a winning effort.