Inheriting the ALCS Game 4 start for Boston after Tim Wakefield was needed in relief in Game 3, Derek Lowe pitched a perfect first inning for the Red Sox. His counterpart Orlando Hernandez walked both Manny Ramirez and David Ortiz but escaped the first without allowing Boston to score.

Hideki Matsui led off the second with a line drive double down the left field line and advanced to third when Bernie Williams grounded out to second. However, he was tagged out at home, trying to score on a ground ball hit to short by Jorge Posada.

With Derek Jeter on base after a ground ball single to left, Alex Rodriguez propelled a two-run shot over the Green Monster in the third. After perfect third and fourth inning, Orlando Hernandez issued a four-pitch lead off walk to Kevin Millar in the fifth. Millar was erased from the bases when Bill Mueller hit into a fielder's choice and the Yankees chose to take out the lead runner. However, Mark Bellhorn also walked, giving the Red Sox runners on first and second. Johnny Damon then hit a ground ball to Miguel Cairo, who threw to second to get Bellhorn out, but New York was unable to turn two. Mueller advanced to third, and Damon was safe at first. Orlando Cabrera drove in Mueller with a ground ball single into left field. Hernandez subsequently walked Ramirez to load the bases for Ortiz. Ortiz hit a line drive single into center, scoring Mueller and Damon while advancing Ramirez to third. Jason Varitek struck out, stranding Ramirez and Ortiz, but Boston left the fifth with a 3-2 lead.

The Red Sox pulled Lowe one out into the sixth after he Matsui hit a fly ball into center beyond the grasp of Damon for a triple. After Mike Timlin relieve Lowe, Williams hit a high bouncer off the mound. If Cabrera had been able to bare hand it, he probably would have stopped Matsui at the plate, but the ball got past him and Matsui scored on the single. Timlin then issued a four-pitch walk to Posada. During Ruben Sierra's at-bat, Williams attempted to take third when a ball bounced in the dirt behind home plate and got away from Varitek. Varitek quickly recovered and threw to third, where Mueller applied the tag before Williams reached the base, though Posada took second. When his at-bat resumed, Sierra bounced a ball up the middle for a single that advanced Posada to third. Bellhorn made a poor throw trying to get Sierra at first, but Millar successfully blocked it before the ball could skitter away and allow Posada to score. Posada instead waited for Tony Clark to drive him in with a ground ball single to second. Timlin went ahead and walked Cairo to load the bases, but Jeter grounded out to second, sparing Boston further damage.

Tanyon Sturtze relieved Hernandez prior to the sixth and prevented the Red Sox from eliminating the Yankees' new 4-3 lead. Despite his troubles in the sixth, Boston sent Timlin back out to the mound in the seventh only to pull him after he walked ARod and retired Sheffield. Keith Foulke came in and dispatched the next two batters. Sturtze responded with a perfect inning, Foulke held the Yankees in the top of the eighth, and New York brought in Mariano Rivera in the bottom of the eighth. Ramirez managed a single off Rivera, but Boston couldn't knock him in. While Foulke gave up a lead off walk to Jeter in the ninth, he kept the Yankees off the board for another inning.

Millar then led off the bottom of the ninth with a walk at which point the Red Sox pinch-ran for him with Dave Roberts. After three pick-off attempts, Rivera delivered a pitch to Mueller and Roberts stole second, putting him in position to score and tie the game at 4 when Mueller drove a ground ball up the middle into center for a single. Pinch-hitting for Bellhorn, Doug Mientkiewicz laid down a sacrifice bunt to advance Mueller to second. Damon then hit a grounder straight to Clark, but Clark bobbled it, allowing Damon to reach first safely and Mueller to advance to third. Cabrera subsequently struck out, however Ramirez walked, loading the bases. To the disappointment of the Fenway crowd, Ortiz popped out to second, leaving the runners stranded and the game tied.

Tom Gordon and Alan Embree relieved their respective closers prior to the 10th, taking the tie into the 11th. Cairo led off the 11th with a line drive down the right field line for a single and advanced to second on a Jeter sac bunt. Cabrera made a diving stop of an ARod line drive, and then Boston called for Embree to intentionally walk Sheffield before bringing Mike Myers in to face Matsui. Myers issued a four-pitch walk to Matsui, loading the bases, so the Red Sox replaced him with Curt Leskanic, who successfully retired Williams to end the inning. Boston provided far less resistance for Gordon in the bottom of the inning.

Leading off the 12th, Posada dropped a fly ball into shallow right field for a single. However, Leskanic maintained the tie for another inning. New York sent Paul Quantrill out for the bottom of the 12th, and Ramirez led off the inning with a line drive into left field for a single. Making up for his disappointing at-bat in the ninth, Ortiz dropped a fly ball into the far right corner of the bullpens in right field for walk-off, two-run homer. After avoiding the sweep with a 6-4 win, Boston will try to hold off the Yankees again today in front of the fans who purchased tickets for the rain postponed Game 3. If the Red Sox win, the two teams will head directly to New York, where the series will pick up with Game 6 tomorrow.