BOSTON -- Nine months late, the Dodgers won a series from the Red Sox while showing everything that's right and wrong with a bullpen as the Trade Deadline approaches.

In a 7-4 win over the defending champs, closer Kenley Jansen lobbied his way into a tie game and put down two Boston rallies. Dylan Floro was credited with the victory and Joe Kelly, a Boston October hero, returned to Fenway Park and earned his first Dodgers save by striking out the game's last two batters and his former teammates. It was the first Interleague series the Red Sox have lost at home since 2014.

• Box score

"You can see the way those guys played and their intensity and focus, they wanted this series," Dodgers manager Dave Roberts said. "They wanted to get the second half off on a good foot. I thought it was very focused baseball and two very equal ballclubs. These are two clubs that can handle four-hour games."

Actually, it was five hours and 40 minutes, because Pedro Báez allowed back-to-back solo home runs to Xander Bogaerts and J.D. Martinez when asked to protect a two-run lead in the eighth inning. Roberts said Baez was tipping pitches so Red Sox hitters knew what was coming and he went to the mound to tell him. Baez followed with three strikeouts.

The Dodgers stayed alive in the bottom of the ninth after Zac Rosscup walked Jackie Bradley Jr. on four pitches. Yimi Garcia took over, Bradley was bunted to second and Mookie Betts was intentionally walked. Then Roberts disregarded custom and brought on Jansen.

"It was the highest leverage of the game," Roberts said.

Jansen saw it coming. He said he picked up the bullpen phone and called the dugout.

"I tell Doc [Roberts] that I'm already hot and I'm ready for [Rafael] Devers, [who lined out to a sprawling Joc Pederson]," said Jansen, who then struck out Bogaerts.

"Listen, the whole year these guys pick me up," Jansen said. "Just wanted us to win this ballgame, beat the defending champ. You could see them knowing that they want to beat us bad, and we try to do the same thing. It's already extra innings, their best lineup is coming up. Men on base. I respect all my guys, but I'd rather take the ball against the best hitters."

Jansen also pitched out of a jam with the winning run on second base in the 11th inning, then turned it over to Floro. Meanwhile, the offense that was staked to a 4-2 lead on A.J. Pollock's three-run homer and RBI single got to the Boston bullpen in the 12th on a bases-loaded walk by Max Muncy, an RBI single by Alex Verdugo and a run-scoring fielder's choice grounder by Russell Martin.

With one out and one on in the bottom of the 12th, on came Kelly to lock it down by striking out Brock Holt and Jackie Bradley Jr.

"Couldn't have scripted it better," Kelly said. "I loved my time here. That was definitely fun. Kenley was massive. He stepped up big-time. Always inspires bullpen guys to see a leader do that and keep us in the game."

"We were just fortunate [Nathan] Eovaldi was not in the building," Roberts said, referring to the now-injured Red Sox pitcher who threw seven innings of relief that night.