Boston Celtics

TMZ has obtained exclusive VIDEO of the postgame screaming match between Kevin Garnett and Carmelo Anthony following Monday night's Celtics vs. Knicks game ... and it's clear both guys were ready to fight.

The incident went down in front of the Celtics team bus inside Madison Square Garden -- just a short time after things got physical between the two NBA superstars on the court.

In the video, both men can be seen yelling and approaching each other aggressively as security scrambles to keep them apart.

It's unclear exactly what the guys were saying to each other -- but we definitely heard someone use the n-word a couple of times.

Eventually, security was able to separate the big men ... and KG boarded the team bus.

After the game, Anthony told reporters it all started when Garnett spewed some trash talk during the game that "crossed a line."

"There’s certain things that you just don’t say to men, another man,” Anthony said.

Boston Celtics star Leandro Barbosa doesn't need a red suit and a beard to play Santa -- in fact, the guard handed out piles of gifts to underprivileged children in Boston yesterday ... wearing nothing but normal street clothes.

A rep for Barbosa tells TMZ, he threw a giant holiday party at the Lenox Housing Development for roughly 80 children -- between the ages of 6 and 16 -- just because he felt like giving back to the community.

Along with a huge array of gifts -- one for each kid -- Barbosa brought 30 delicious PIZZAS.

Boston Celtics superstar Rajon Rondo crashed the boards at a Boston high school today ... guest teaching a freshman algebra class ... on his day off.

Rondo -- rolled into Ms. Oshodi's class at Burke high school this morning -- where he taught the kids how to solve for X (it's 14 ... we think).

Rajon didn't stop there ... the 26-year-old -- who attended the University of Kentucky -- also visited nearby Harbor Middle School to preach the value of a quality education.

And get this -- we're told Rondo planned the visits by himself ... without the help of any public relations personnel ... just because he wanted to.

Rajon will be back on the court tomorrow to face off with the Washington Wizards -- a team that's currently 0-2 ... and with the power of math, we are able to determine they're horrible.

Thanks math!

Lil Wayne surfaced in his court side seats for the Miami Heat season opener -- despite his recent health crisis -- but as TMZ reported ... he had to trade in his private jet for a luxury bus to make the return trip.

Weezy was in his usual primo seats to see the NBA champs defeat the Boston Celtics on Tuesday night.

Sources close to Wayne tell us he rode a private luxury tour bus from his mother's home in Louisiana back to Miami ... sometime on Monday.

As we told you ... Wayne is under strict orders from his doctors to stay off airplanes in the wake of two mid-air medical emergencies last week -- in which he suffered 2 seizure-like episodes.

We doubt the NBA action was doctor prescribed -- but sitting court side to see LeBron and D-Wade in action can't hurt.

The Boston Celtics hate her son's guts ... but Ray Allen's mom tells TMZ, she still loves her boy's old teammates like they were her own children -- even though Ray ditched 'em to join the Miami Heat.

It's no secret -- Ray's old teammates Kevin Garnett and Paul Pierce are extremely bitter Ray jumped ship to the Heat following last season ... after the Heat whooped the Celtics in the Eastern Conference Finals.

During a news conference last month, Garnett said he had cut Allen out of his life -- "I don't have Ray's number anymore. I'm not trying to communicate." Pierce said, "I was very surprised by Ray's decision. I thought we would finish our careers together."

For his part, Allen has said he hasn't spoken to any of his old teammates since they split.

But now that both teams are set to face off tonight in Miami, Allen's mom Flo Allen-Hopson tells TMZ, she isn't holding the same grudge, claiming, "I love the guys. They’ve been in our home. They’ve been in Ray's home. If they came to my home tomorrow, if they wanted me to cook for them, I would because they are all our sons."

Flo -- who says she's rooting for the Heat now for obvious reasons -- tells us, she plans to hug Garnett and Pierce tonight when she attends the game.