When Joel Casamayor and Jose Armando Santa Cruz meet in the ring the world will see what happens when allies become foes.

Cuba’s best fighter Casamayor (34-3-1, 21 KOs) defends the WBC lightweight title against number one ranked Santa Cruz at Madison Square Garden on Saturday Nov. 10. Both are extremely familiar with each other on this match that will be shown on HBO pay-per-view.

“We sparred a few times,” said Santa Cruz (25-2, 14 KOs), who was hired by Casamayor because of his long thin build and relentless style. “I helped him prepare for his second fight against Diego Corrales.”

Santa Cruz, 27, lives in Lincoln Heights, a small hilly section of East Los Angeles, and comes from a family of boxers. He’s twice attempted to win a world title but has been thwarted each time.

First by David Diaz in August 2006, where Santa Cruz was beating him for nine rounds when he was stopped in shocking fashion by the Chicago fighter. Referee Richard Steele stopped the fight at 2:26 of the 10th.

“I was caught with a good punch,” says Santa Cruz whose appearance outside the ring belies his persona inside.

A year earlier, in August 2005, it was Fernando Trejo who was sustaining heavy damage against Santa Cruz but rallied with 41 seconds left in the 10th round. Santa Cruz was stopped in that fight too.

Maybe this fight will be different? It’s not going to be held in the month of August.

“I don’t know what it is,” said Rudy Hernandez who trains and manages Santa Cruz. “Nobody trains harder than Santa Cruz. I never have to tell him to do anything. He just comes to the gym and does his work.”

Hernandez, whose brother Genaro “Chicanito” Hernandez was a long reigning junior lightweight champion, knows there are only so many chances a fighter can receive at a title shot.

Title shots mean big money.

“If you can’t make big money why continue fighting,” Hernandez says. “That’s why anybody should get into this sport for the big money.”

Now it’s come to Casamayor, one of the most talented lightweights in the last 10 years. Though he’s a friend of his opponent it won’t stop the crafty southpaw from using every single trick in his thick book. Especially that he’s back with trainer Joe Goossen.

Remarkably, it’s Casamayor’s first title defense that he won from Diego Corrales last year.

“I haven’t fought in a year but I feel great,” says Casamayor.

Ironically, it was Santa Cruz who helped him prepare for that fight and others.

“The kid is top five or top 10, he was beating David Diaz easily,” said Casamayor respectfully about Santa Cruz. “He may be better than all three Diazs.”

Though Casamayor thinks his foe is better than Juan, David and Julio Diaz, he is Casamayor. Enough said.

“He’s a good fighter. I sparred with him he was one of my main sparring partners, but that was sparring,” said Casamayor. “He has a suspect chin and he won’t be in there with David Diaz, he will be in there with Joel Casamayor.”

Team Santa Cruz knows what to expect.

“We need to take advantage of the opportunity that’s being presented, no excuses. I know were underdogs in this fight and to be honest the public favors Casamayor,” said Hernandez. “The only thing I’m asking is when we win nobody comes up with excuses that Casamayor was too old or too rusty. That’s all we ask.”

Casamayor shrugs off any feelings for his former ally.

“It’s going to be exciting,” he says.