The intimidation attempt didn't work against the Charlotte Bobcats.
"I just told him he hits like my grandma," Najera said.
The little-used Najera ended up burying a clutch 3-pointer, Gerald Wallace scored 19 points and hit the clinching free throws with 3 seconds left, and the Bobcats overcame top scorer Stephen Jackson's ejection to stun the Celtics 94-89 on Monday night.
"This is a wonderful victory for us," coach Paul Silas said.
Ray Allen scored 25 points, but attempted and hit only two 3-pointers to leave him two shy of breaking Reggie Miller's NBA career record of 2,560. Paul Pierce added 22 points and Garnett grabbed 14 rebounds.
But Boston, coming off emotional games against powers Dallas and Orlando, dressed only 10 players and ran out of gas in the fourth quarter against a potential first-round playoff opponent.
So not only did Allen not get to celebrate a milestone, the Celtics' lead in the Eastern Conference was trimmed to one game over Miami in a performance that left a sullen locker room.
"I thought our guys came in with their cool game today and thought they were going to win it, maybe because of our jerseys," coach Doc Rivers said.
The Celtics could never have expected who helped bury them in a testy game that included five technical fouls and yet another emotional outburst by Jackson.
Gerald Henderson scored 15 points filling in for Jackson and Najera's 3-pointer with 1:57 left put Charlotte ahead 89-83.
"I don't think he made a 3 all year," Garnett said.
It was his sixth in 16 attempts. The 34-year-old Najera was asked after the game if toughness was one of his attributes.
"I think that's about the only thing I have left," Najera said, smiling. "And I make a 3 now and then."
The Celtics got within 91-89 in the final seconds before Wallace put it away at the line as Charlotte salvaged one game in a brutal three-game homestand against that also included Miami and Dallas.
They didn't even need their hothead shooting guard, who is up to 13 technical fouls this season.
Jackson was sent to the locker room with 1:38 left in the second quarter, hit with consecutive technicals when he wouldn't stop complaining about being called for a foul on Garnett.
"He just kept talking and talking and talking, and of course they gave him the ejection," Silas said. "I have to commend the guys, though. Once he went out our guys stepped up."
The Celtics had no depth at small forward or center with big man Semih Erden (abductor strain) added to the long injury list on Monday.
He was sidelined along with Shaquille O'Neal (leg), Jermaine O'Neal (knee), Delonte West (wrist) and Marquis Daniels, who bruised his spinal cord in a scary injury Sunday. Boston's thin bench included Avery Bradley, called up from the NBA Development League earlier Monday.
What the Celtics lacked in numbers, they tried to make up with aggression.
Charlotte's Kwame Brown had to be separated from Kendrick Perkins after Perkins' hard foul in the second quarter. The scuffle produced technical fouls for Brown and Pierce. Garnett picked up a technical in the third quarter.
Allen looked to be on pace to break the 3-point record when he buried his first long-range shot 51 seconds in. But his second 3 didn't come until midway through the third quarter.
They were the only 3s Allen attempted on a 9 of 17 shooting night. Boston shot just 41 percent from the field and was outrebounded 50-37.
"We kind of messed around with the game and then we tried to win it in the fourth with nothing in the tank," Rivers said.
Rivers said he exchanged text messages with Daniels on Monday and said he's "doing a lot better" but it's "going to take a while" before he can play again, possibly forcing the team to make a roster move. ... Silas called Allen one of the greatest shooters in league history, but said he'd like to see him face off against his former teammate in Seattle, "Downtown" Freddie Brown. ... Rivers isn't concerned with the increased criticism Garnett has received for his behavior. "I think all these people who call them out will take them on their team right now," he said. ... Bradley said he was up at 5 a.m. Monday to catch a flight from North Dakota to Charlotte through Minneapolis. ... South Carolina football coach Steve Spurrier attended the game as a guest of Rivers.