The three-hit game was Napoli's second of the season -- and first since April 25.
The home run was Napoli's first since June 17, snapping a drought of 73 at-bats.
"Yeah, I mean I've been feeling a lot better since the All-Star break," said Napoli. "But yeah, I put it together tonight. What I was working on I brought it into the game. It was a good feeling to make good contact and I've been seeing the ball well."
Napoli wants to stay with the Red Sox, the team he's played for since 2013.