Bronx, NY -- (Sports Network) - Jason Giambi belted a two-run, pinch-hit homer in the seventh inning to tie the game and singled home the winning run in the bottom of the ninth, as the New York Yankees salvaged the finale of a three- game series against the Boston Red Sox with a 3-2 victory in what was likely the last meeting between these storied rivals at the current Yankee Stadium.

Not only did the Yankees manage to avoid a sweep, but they likely saved their season. A loss would have left New York eight games behind Boston in the AL wild card race, but the victory enabled the Yankees to pull within six games with 29 to play. The teams will also meet for three games at Fenway Park to conclude the season in September.

Boston starter Jon Lester cruised into the seventh inning with a four-hitter and a 2-0 lead. He retired the first two batters of the inning before Cody Ransom's double into the left field corner ended the lefty's day. Hideki Okajima took the mound for Boston and Giambi, pinch hitting for Jose Molina, clubbed an 0-1 pitch over the center field wall for his 27th homer to tie the game.

The Red Sox stranded a runner at second base in the top of the ninth against Mariano Rivera (5-5) and the Yankees pulled off their eighth walkoff win in the bottom of the inning.

Xavier Nady led off the home ninth against Justin Masterson (4-4) with a single up the middle. After Robinson Cano failed to bunt and lined out to third, pinch runner Brett Gardner stole second and Hideki Matsui was given an intentional walk. Ivan Rodriguez drew another free pass to load the bases for Giambi, who greeted closer Jonathan Papelbon with a single to center on an 0-2 pitch to plate Gardner with the winning run.

"That's a great win for us," said Yankees manager Joe Girardi. "It was a game we thought we had to win. If you lose this game, it's an extremely tough series."

Lester was brilliant for Boston, charged with one run and five hits over 6 2/3 innings. He did not walk a batter and struck out eight.

"I thought [Lester] was tremendous," Sox manager Terry Francona said. "His fastball was explosive. It's a shame the way the game ended."

Mike Mussina started for New York and left after seven solid innings. He yielded two runs on five hits with two walks and six strikeouts.

"Mike Mussina was excellent today," Girardi remarked. "He's pitched so well for us all year. He was the reason we had a chance. He kept us in the game."

New York finished with a regular-season record of 484-285-4 against the Red Sox at Yankee Stadium. The only way these teams will meet in the postseason is if the first-place Tampa Bay Rays completely collapse and the Yankees and Red Sox both pass them to earn playoff berths, then each win a first-round series and meet in the ALCS.

"At this point we're trying to get wins and this was a big one," said Yankees shortstop Derek Jeter. "It doesn't get any easier. We need to come [back this weekend] ready to play."

The Red Sox broke the stalemate in the fifth with a pair of runs. Jed Lowrie singled with one out and Alex Cora appeared to lean into a 1-2 pitch to put runners on first and second. Jason Varitek then singled into right field to plate Lowrie with the game's first run. Cora raced to third on the play and scored when Jacoby Ellsbury beat the relay on a potential double-play grounder.

Boston threatened in the sixth after Dustin Pedroia led off with a single and Kevin Youkilis was hit by a pitch with one out. Jason Bay followed with a slow bouncer toward third and Alex Rodriguez missed the advancing Pedroia, who appeared to run onto the infield grass and out of the baseline to elude the tag. Rodriguez still got the out at first, and with two runners in scoring position, Mussina fanned Mark Kotsay to end the inning.

The Yankees also came away empty in the sixth after their first two batters reached base. Johnny Damon was hit by a pitch to start the inning and Jeter followed with a single. Bobby Abreu then flied to deep center, allowing Damon to reach third, but Rodriguez fouled out behind the plate and Nady flied to shallow center field.

Rodriguez was 0-for-4 with three strikeouts and also failed in a big spot in the first inning. After Jeter and Abreu each singled with one out, Rodriguez struck out before Nady grounded to third.

Game Notes

Giambi homered in consecutive at-bats, having also homered in the ninth inning of Wednesday's 11-3 setback...Jeter was 3-for-4 and is 11 hits shy of Lou Gehrig's record of 1,269 hits at Yankee Stadium...The Yankees earned their 39th come-from-behind win of the season, most in the majors...Kotsay, in his first game with the Red Sox after being acquired from Atlanta, was 1-for-4 with a double...Boston leads the season series, 8-7...The Red Sox were the Yankees' first opponent in Yankee Stadium, as Babe Ruth christened the new ballpark with a home run in New York's 4-1 triumph on April 18, 1923...Before the game, the Yankees optioned pitcher David Robertson to Triple-A Scranton/Wilkes-Barre and recalled pitcher Alfredo Aceves from the minor league affiliate...The Yankees will host Toronto for a three-game series this weekend, while the Red Sox head home for the weekend to take on the Chicago White Sox.