BOSTON — It did not take first baseman Lyle Overbay long to recognize the magic brewing in Boston’s clubhouse last season.

And that was way back in February and March.

“The whole spring training they came together. As a team they were jelling,” Overbay said of the defending World Series champions, who cut him late in spring training before he signed with the New York Yankees. “When I was with the Yankees, I was like, ‘These guys are the team to beat,’ just the way they go about their business, and it was from Day One in spring training.”

Now with the Milwaukee Brewers, Overbay could not have scripted a better dose of revenge.

Long after spending an hour in the dugout before the game watching as Boston and its fans celebrated the 2013 World Series championship with a lavish party and ring ceremony Friday, Overbay delivered a tie-breaking, two-run double in the ninth inning to lead the Brewers to a 6-2 win over the Red Sox, spoiling the 103rd home opener in Fenway Park history.

“I’ve got to make sure that they know, bring them down to our level,” Overbay said. “Make sure they know that we’re jealous and we want a piece of that.”

Center fielder Carlos Gomez went 4-for-5 with two RBIs and catcher Jonathan Lucroy had a home run and double as the Brewers scored more runs than they had in their first three games combined.

Most of the damage did not come until the ninth, though.

After Boston’s Burke Badenhop tossed two scoreless innings of relief, Edward Mujica (0-1) came on to start the ninth and surrendered a leadoff double to left fielder Khris Davis, who moved to third on a sacrifice bunt by second baseman Scooter Gennett. Overbay then looped a double down the right-field line, and Gomez and third baseman Aramis Ramirez added RBI singles.

Boston signed Mujica from St. Louis during the offseason, and the Brewers were familiar with the former Cardinals’ closer.

“They came out swinging against Mujica,” Boston manager John Farrell said. “At the same time, Edward’s had a lot of success against that lineup, mislocated a couple of balls and he paid for it.”

Right-hander Francisco Rodriguez then pitched a 1-2-3 ninth to close it out.

Third baseman Will Middlebrooks homered for the Red Sox.

The game began with Boston starter Jake Peavy being hit hard.

Lucroy led off the second with a solo shot that cleared the Green Monster in left field, and Gomez made it 2-0 with an RBI single.

“There was some excitement, but it’s something I’ve been around long enough that you channel that,” said Peavy, who allowed two runs on six hits over six innings, walking two and striking out four. “The toughest thing is in spring training you cannot duplicate how hard you go. There’s an extra gear. It was good today to get off from the spring.”

Boston plated a run in the bottom of the inning when first baseman Mike Napoli walked, moved to third on center fielder Grady Sizemore’s single and scored on a throwing error.

Middlebrooks tied it with one out in the third, belting a first-pitch fastball from Brewers starter Marco Estrada into the seats above the Monster.

Estrada yielded two runs — one earned — on four hits over 5 2/3 innings, walking three and striking out six.

Brewers right-hander Brandon Kintzler (1-0) picked up the win with one inning of scoreless relief.

“Not just today, this is a real intimidating place to come,” said Brewers manager Ron Roenicke. “It’s tradition, but it’s always just the crowd, the adrenaline that flows in this place is amazing.

“When your team comes in and plays well any time — today was great — but any time, I think it’s a big plus.”

NOTES: Boston had won nine straight home openers, which was the longest active streak in baseball. … The opening ceremony highlighted all of the city’s recent championships. Former Red Sox players Mike Lowell, Pedro Martinez and Jason Varitek carried the World Series trophies from 2004, 2007 and 2013 to the mound, former Patriots Tedy Bruschi, Ty Law and Troy Brown toted New England’s Super Bowl trophies from 2001, 2003 and 2004. Former Celtic Leon Powe brought the NBA championship trophy from 2008 and former Bruin Mark Recchi lugged the Stanley Cup from 2011. … Brewers OF Ryan Braun, suspended for the final 65 games last year for violating the league’s policy on performance-enhancing drugs, was booed during his introduction and before each at-bat. He went 0-for-5. … RHP Marco Estrada was 4-0 with a 2.16 ERA during spring training, finishing with 17 straight scoreless innings.