After leading the Red Sox to a World Series title in 2013 but misfiring on most free agent and trade decisions since then, Ben Cherington is out as general manager.

Last night, the Sox announced the hiring of Dave Dombrowski, the former Detroit Tigers general manager who was let go to pursue other opportunities earlier this month, as the new president of baseball operations. Dombrowski will assume responsibility for “all baseball operations matters effective immediately” and will report directly to Red Sox principal owner John Henry and chairman Tom Werner.

In a written press release, the Sox said that Cherington “declined the opportunity to continue as general manager, but has agreed to assist Mr. Dombrowski during the transition.” To have come back with Dombrowski having all the power would’ve left Cherington in an awkward position.

A press conference will be held at 2 p.m. today to introduce Dombrowski. Cherington could not be reached for comment last night.

The move may come as a surprise, especially since the Red Sox have been adamant that Cherington would be their general manager “for a very long time,” as Henry said on June 2. “There are adjustments we need to make as an organization. Ben will make those adjustments, and he’ll lead that process. I think he and his people are the right people to do that.”

Cherington took over as GM of the Red Sox in 2011 when Theo Epstein left to join the Cubs front office. In his first season as GM, Cherington hired Bobby Valentine as manager and watched the Sox win just 69 games.

But he pulled all the right strings prior to the 2013 season, adding John Farrell as manager while signing free agents Koji Uehara, David Ross, Jonny Gomes, Mike Napoli and Shane Victorino, among others, as the Sox won 97 games on their way to a World Series title.

In 2014, Cherington appeared to lose his touch. Signing A.J. Pierzynski as the catcher was a giant mistake, and the mid-season addition of Stephen Drew may have stunted Xander Bogaerts’ development. Cherington was forced to trade almost 25 percent of the active roster by the July 31 deadline, an opportunity for the Sox to add immense talent to their farm system.

But almost all of his trade deadline moves, with the exception of acquiring Eduardo Rodriguez for reliever Andrew Miller, have looked like failures. Jon Lester did not re-sign after he was traded last year for Yoenis Cespedes, who was eventually flipped for Rick Porcello. Porcello was signed to a four-year, $82.5 million extension on Opening Day and owns a 5.81 ERA. Trading John Lackey for Allen Craig and Joe Kelly has looked like one of the worst trades in recent Red Sox history.

Cherington then built the worst starting rotation in the American League and committed $183 million to Pablo Sandoval and Hanley Ramirez.

However, Cherington can’t be knocked for his ability to assemble a top-ranked farm system.

“The Red Sox baseball operations group and Ben Cherington deserve extraordinary credit for the young, talented players that have broken through at the major league level, and I see outstanding potential in the talent still developing in our minor leagues,” Dombrowski said in a statement. “I am anxious to get to Boston and to focus on playing an important role in helping this great franchise continue its recent history of world championships.”

In Dombrowski, the Red Sox will turn to a proven leader in the industry when it comes to finding talent.

“Although I did have other potential options within baseball, there was no option that stood out as clearly as the chance to come to Boston and win with the Red Sox,” Dombrowski said in a statement. “Boston is a baseball city like no other and its history and traditions are unique in our game. I expressed to John and Tom that Boston would be my absolute top choice and am honored to have the chance to serve Red Sox Nation.”

Dombrowski took the Tigers from consistent losers when he was hired in 2001 to consistent winners, leading them to World Series appearances in 2006 and 2012. They made the ALCS in 2013, when they lost in dramatic fashion to the Red Sox, and have won the last four AL Central titles.

Dombrowski was named the Montreal Expos GM in 1988 at the age of 32, then left for the Florida Marlins in 1992 and helped them win a World Series in 1997. He also has a close relationship with Henry, who owned the Marlins in the late 90s until he bought the Red Sox with Werner in 2002.

“I have known Dave very well for a long time,” Henry said in a statement. “Tom and I have no doubts that Dave is the right person to strengthen our baseball operations group going forward.”