Adam Warren stuffed the defeat into his luggage because he surrendered a laser home run to Mike Napoli that landed in the center-field seats.

Yet the blame for the Yankees’ 8-7 loss to the Red Sox in 11 innings that was witnessed by 38,138 — Fenway Park’s largest of the season — belonged to CC Sabathia.

“We scored seven runs — not being able to win that game is unacceptable,’’ said Sabathia, who was torched for seven runs and nine hits (two homers) in five-plus innings. “I sucked. I wish I had an excuse. It sucks, it’s embarrassing. I will try and work through it and figure out how to stop hurting the team and start helping.’’

The loss dropped the Yankees seven games behind the AL East-leading Red Sox, who took two of three in the series.

Staked to a 3-0 lead after two innings, Sabathia gave up four in the third when Napoli hit a three-run homer and Dustin Pedroia drove in a run. Jonny Gomes homered off Sabathia to start the fifth to give the hosts a 7-4 advantage.

The Yankees chipped away with two runs in the sixth and two more in seventh to tie the score, 7-7, and allow Sabathia to avoid a loss.

Still, that did very little to mollify Sabathia, who is 0-1 with a 10.00 ERA and has given up 17 hits in nine innings across his last two starts.

“I have to make better pitches,’’ Sabathia said.

The lefty, who turned 33 yesterday, was hurt by consecutive 1-2 pitches in the third to David Ortiz, who singled to center, and Napoli, who hit a 93-mph fastball deep into the seats on top of the Green Monster.

Sabathia, whose ERA is at a very chubby 4.37, recalled struggling in 2008 with Cleveland. He said it turned around when he was dealt to Milwaukee and benefitted from a change of scenery. That, of course, isn’t going to happen again.