Boston ? Kevin Youkilis scored the go-ahead run on a passed ball after his third extra-base hit, and the Boston Red Sox rallied to beat the New York Yankees, 9-7, in the major-league opener Sunday night.

Boston erased a 5-1 deficit against CC Sabathia and defeated the defending World Series champions in the first night opener in the history of 98-year-old Fenway Park.

Jorge Posada and Curtis Granderson hit back-to-back homers off Josh Beckett to give the Yankees a 2-0 lead in the second inning. It was 7-5 in the bottom of the seventh when Marco Scutaro singled and Dustin Pedroia tied it with an opening-day homer for the second straight season.

Youkilis then doubled with two outs, took third on Damaso Marte’s wild pitch and scored when the left-hander’s high pitch bounced off Posada’s glove. Pedroia added an RBI single in the eighth.

Hideki Okajima pitched a scoreless inning to get the win and Jonathan Papelbon worked the ninth for the save.

Chan Ho Park recorded just two outs while picking up the loss in his Yankees debut. The right-hander was charged with three runs and three hits.

Former Red Sox ace Pedro Martinez got a warm greeting when he threw out the ceremonial first pitch.

The real starters didn’t do as well.

Sabathia gave up five runs and six hits over 51/3 innings in his second poor opening-day start since he joined New York for a $161 million, seven-year contract.

Beckett allowed five runs and eight hits in 42/3 innings. It was the worst of five opening-day starts for the right-hander, who had allowed just four runs in 222/3 innings in his previous four.

Even two aging singers beloved by Red Sox fans had better nights.

Steven Tyler, lead singer of Aerosmith and a Boston-area resident, sang “God Bless America” during the seventh-inning stretch.

Neil Diamond, whose “Sweet Caroline” is played at Fenway Park after the top of the eighth, then stepped onto the field along the right-field line to sing it in person. The Brooklyn native wore a blue Red Sox hat with a red “B” and a dark jacket with the words “KEEP THE DODGERS IN BROOKLYN” on the back.

The Red Sox were more concerned with the team from the Bronx.

The Yankees began the season as champions for the first time since they beat Kansas City, 7-3, behind Roger Clemens in the 2001 opener. They finished that year in the World Series, but lost to the Arizona Diamondbacks in seven games.

The last time the Red Sox and Yankees met in an opener was in 2005 following Boston’s first championship since 1918.