BOSTON — This was not a happy birthday for CC Sabathia — one big problem for the Yankees, a team with a multitude of them.
Sabathia, who turned 33 yesterday, was hit around like a piñata as he had his worst outing of the season last night in a terrible, 8-7 walk-off loss to the Red Sox at Fenway Park.
It was a swing game the Yankees had to have, and the big lefty came up small.
Sabathia lasted only five-plus innings as he surrendered nine hits and seven runs, all earned. He gave up two mammoth home runs, a three-run shot to left-center by Mike Napoli that went far over the Green Monster in the third inning off a 93-mph fastball, and a leadoff home run to Jonny Gomes in the fifth off a changeup.
The Red Sox won it on a two-out home run to dead center by Napoli in the 11th inning on a 3-2 pitch from Adam Warren, ending the four-hour, 46-minute marathon.
Sabathia could not put away hitters, and as a result put the Yankees in a huge hole. This was a day where young Matt Harvey once again made it clear he not only is the Ace of the Mets, but the Ace of New York.
When the night was over, Sabathia was the most frustrated he has ever been as a Yankee.
“We scored seven runs and not being able to win that game is unacceptable,’’ Sabathia said. “I suck. I wish I had an excuse or something. I’m not very good. It sucks, it’s embarrassing. I have to try to work through it, figure something out and stop hurting this team [and start] helping.’’
Sabathia did not figure in the decision. He owns an 0-2 record on his birthday with a bulging 7.48 ERA in four starts. He walked two and struck out five last night as he was staked to a 3-0 lead, but he gave up seven runs over the third, fourth and fifth innings.
This was a night the Yankees needed Sabathia so badly to be the ace again. It was the second straight start when Sabathia could not get the job done; in those last two outings, he has lasted only nine innings and has surrendered 15 runs — 10 earned — while giving up 17 hits.
It is ugly out there for the pitcher who used to be the Yankees’ ace.
Earlier in the day, the Yankees learned Alex Rodriguez will not be joining them for a while because of his Grade 1 quad strain, not to be confused with Derek Jeter’s Grade 1 quad strain.
There are no injury issues with Sabathia. He just is not getting the job done in any way and with all the other issues surrounding the Yankees, his performance may be the most disconcerting of all.
Those two home runs allowed put Sabathia at 23 allowed for the season, a career high. His previous career high was 22, set last year, and it is only July 22. Sabathia has given up nine home runs over his last six starts.
He has no fear factor anymore.
Hiroki Kuroda, who has lost just one of his last seven starts, has taken over the ace role for the Yankees. The Yankees desperately need Sabathia to get it together.
Sabathia has never really struggled as a Yankee.
“In 2008 in Cleveland I wasn’t able to pitch well, but I was able to pitch well in Milwaukee,’’ he said.
Change of scenery changed things around then.
“I have to pitch better,’’ Sabathia said. “The [Red Sox are] leading the division. It’s so frustrating going up 3-0 and me just going out there and blowing it.’’
The Yankees are seven back of the Red Sox. They have made the postseason on four occasions after trailing in their division by six or more games after the All-Star Break since 1969.
Considering all their injuries, they have no shot if Sabathia cannot close out hitters.
kevin.kernan@nypost.com