Red Sox 11, Yankees 1: Mike Napoli hit a grand slam and Felix Doubront pitched six strong innings as visiting Boston evened the series with New York.

Daniel Nava added a three-run homer among four hits and Mike Carp recorded an RBI double in a five-run third for the Red Sox. Doubront (4-2) allowed a run on six hits while striking out six to snap a five-appearance winless streak.

The Yankees elected to intentionally walk David Ortiz in the third inning, loading the bases for Napoli. Phil Hughes (2-4) left a 2-2 fastball over the plate and Napoli belted it out to right-center for his fifth career grand slam and a 5-0 lead.

Rookie Jackie Bradley Jr. began the third-inning rally with a double to center and Nava singled before Carp’s double opened the scoring. Hughes lasted 4 1/3 innings and was charged with five runs on seven hits.

The Yankees got a run back in the fourth on Chris Stewart’s sacrifice fly but left seven runners on base in falling for the sixth time in the last seven games. Nava’s blast to right-center in the eighth made it 8-1 and Stephen Drew highlighted a three-run uprising in the ninth with a solo homer.

GAME NOTEBOOK: Stewart left in the fifth inning due to dehydration and was replaced by Austin Romine. … Boston CF Jacoby Ellsbury (groin) missed his second straight game and is questionable for Sunday’s series finale. … Nava’s four-hit game was the third of his career. He went 4-for-5 twice in June 2012.