The Boston Red Sox have been in first place since July 7 and will have to win this weekend's home series against the rival New York Yankees to stay there.

"It's always an exciting series," catcher Jason Varitek said after Boston lost 7-3 to the Cleveland Indians on Thursday night to drop into a tie with the Yankees in the AL East. "It never seems like someone's 20 (games) out. We are fortunate to have (Jon) Lester back in the rotation."

Lester, who is 8-1 lifetime against the Yankees and 2-0 this year, opens the series against Bartolo Colon Friday night.

The Red Sox are 8-1 against the Yankees this season. In 2009, Boston won the first eight games of the series with New York, but the Yankees won nine of the next 10 and also won the World Series.

"We are excited. We feel like we have a great team and so do they," said second baseman Dustin Pedroia. "We are trying to win the division. It's a great division we are in and that's what makes baseball fun."

While the Yankees were completing a sweep of their four-game series in Chicago, the Red Sox were settling for a split of their four-game set with the Indians, losing to former teammate Justin Masterson, who struck out nine in six innings to keep the Indians from falling below the .500 mark for the first time since the third game of the season.

"He's good. We see his best," said Red Sox manager Terry Francona. "I am sure that he enjoys pitching against us. He's impressive."

And Masterson, sent to Cleveland in the Victor Martinez trade in 2009, enjoys pitching in Fenway Park. He's 10-2 in Boston, 15-33 everywhere else. He is also 3-0 against the Red Sox.

Erik Bedard, making his Red Sox debut after being acquired from Seattle, gave up three runs and seven hits in five innings. In his second start since coming off the disabled list, he was on a pitch count and came out after 70 with the score 3-all.

But reliever Franklin Morales (0-1) was greeted by a long double by Travis Hafner and, on the next pitch, Carlos Santana, already 2 for 2 with an RBI, clobbered the ball over the center-field wall for his 16th homer of the season, only his second right-handed. He struck out four times Wednesday night.

Adrian Gonzalez and David Ortiz drove in first-inning runs for the Red Sox, Gonzalez extending his hitting streak to a season-high 14 games with a double that gave him his major league-leading 91st RBI. Josh Reddick hit a solo homer in the fourth inning to tie the game, but that was it for the Boston offense.

Hafner and Kosuke Fukodome also collected three hits in the victory.

Masterson (9-7) threw 118 pitches in his six innings, the pitch count raised when he tied a major league record with four strikeouts in the second inning. His own wild pitch extended that inning and an error by second baseman Jason Kipnis extended the sixth. He became the first Indians pitcher to fan four in an inning since Chuck Finley in 2000.

Hafner's RBI double off Andrew Miller in the seventh and Fukudome's RBI double closed the scoring in the ninth.

NOTES: The game drew 38,477 a post-World War II record at Fenway. ... Recently acquired Ubaldo Jimenez makes his Indians debut when he faces 10-game winner Derek Holland, who shut the Indians out June 4, in the opener of Cleveland<s three-game series in Texas Friday night. ... Jon Lester, 8-1 lifetime against the Yankees and 2-0 this season, faces the Yankees< Bartolo Colon, 0-2 against Boston this year, on Friday night. ... Indians LF Michael Brantley missed his second straight game with a sore right wrist. He will take batting practice Friday. Meanwhile, RF Shin-Soo Choo, on the disabled list with a broken left thumb, is hitting and appears to be ahead of the projected return of the last week of August or first week of September. ... Indians OF Travis Buck accepted his assignment to Triple-A Columbus. ... Cleveland RHP Carlos Carrasco, who started Wednesday night, dropped his appeal and began serving a six-game suspension for throwing high to Kansas City<s Billy Butler. ... Indians 2B Jason Kipnis saw his home run streak end at four straight games. He is the first player in major league history to homer in four straight within two weeks of the start of his career. Graig Nettles, then of the Twins, was the last player to homer in four straight in the first 10 games of his career, doing it in 1968. Kipnis is the first Indians 2B ever to accomplish the feat. ... Miller, in his first Red Sox relief outing, threw 71 pitches in 2 2-3 innings.