BOSTON — Eric Patterson singled home the winning run in the 10th inning, giving the Boston Red Sox a 7-6 victory Saturday night and a doubleheader split that dropped the New York Yankees into a first-place tie in the AL East.

New York and Tampa Bay are both 95-66 with one game remaining in the regular season. Both teams have clinched playoff berths, but the division title will be decided today.

The Yankees need a victory in Boston and a Rays loss at Kansas City to win the AL East. Every other scenario gives the division crown to Tampa Bay, which beat the Royals 4-0 on Saturday.

The division winner also gets home-field advantage throughout the AL playoffs. If the Yankees and Rays finish in a tie, Tampa Bay wins the AL East because it won the season series against New York 10-8.

The team left with the AL wild card opens the playoffs Wednesday in Minnesota. The division winner hosts Texas.

In the first game Saturday, Brett Gardner raced home on an error by second baseman Bill Hall in the 10th inning and the Yankees beat Boston 6-5.

In the nightcap, Hall led off the 10th with a double against Ivan Nova (1-2) and went to third on Kevin Cash’s sacrifice. Hall scored when Patterson lined a single to center.

Robert Manuel (1-0) got the win with two shutout innings.

There were plenty of mistakes throughout the game.

Starting pitchers A.J. Burnett of New York and Daisuke Matsuzaka of Boston each hit two batters. Burnett and Boston relievers Scott Atchison and Hideki Okajima each threw a wild pitch. The Yankees committed four errors, while the Red Sox had two.

The most glaring gaffe came with New York leading 4-2 in the bottom of the fourth.

Daniel Nava led off the inning with a double before Josh Reddick hit a hard grounder to the right of first baseman Lance Berkman, who bobbled the ball.

He picked it up and threw to Burnett, covering the base. Burnett caught the ball, then turned toward third, where Nava had run. But when first base umpire Brian Runge called Reddick safe, Burnett turned his back on Nava and began arguing.

Nava then headed home and, with Robinson Cano and Alex Rodriguez pointing to the plate, Burnett finally threw the ball — past catcher Francisco Cervelli, allowing Nava to score and cut the lead to 4-3. Berkman and Burnett each were charged with an error on the play.

Boston tied it at 4 with the help of another error in the sixth. Ryan Kalish singled, stole second and continued to third on Cervelli’s wild throw. He scored on Yamaico Navarro’s sacrifice fly.

Then it was Boston’s turn in the seventh, when Cervelli singled in the go-ahead run and Berkman scored on Okajima’s wild pitch. But the Red Sox tied it at 6 in the eighth on an RBI single by Nava and a bases-loaded walk to Cash by Nova.