The video a prosecutor played for a judge showed two black boys pounding each other with their fists.
Egging them on was Rodney Lee Sales, a young black man, who repeatedly used a racial slur offensive to African-Americans to encourage them to fight.
St. Petersburg police arrested Sales in November for orchestrating the fight, which he videotaped and posted on MySpace.com.
Sales pleaded no contest to two counts of child abuse Monday in Pinellas-Pasco Circuit Court.
"What I did in that video, your honor, was dumb," said Sales, 18. "If I could, I would take it back."
Judge Linda R. Allan sentenced Sales to five years of probation with the condition that he serve 12 months in the Pinellas County Jail.
"I believe that change should involve incarceration," Allan said.
Assistant State Attorney Joseph Werner had asked for a five-year prison sentence.
"This is the kind of hate that he is instilling in that community. ... That's our community as well," said Werner. "I think the only treatment is to cut the defendant out of the community."
The video was first spotted on MySpace by a person in another state looking for "funny videos," said St. Petersburg Detective Joseph Bross.
The person found the video disturbing and called a television news station in the bay area.
The two boys, who were 5 and 6, slug and kick each other as they roll on the ground. A crowd encourages them.
Werner said Sales rewarded one of the boys with money, though the incident did not involve betting.
"Most of this is mental abuse," said Bross. "They are hitting each other very hard. How it affects a child down the road is hard to say."
Assistant public defender Adam Edmundson told Allan that Sales was remorseful.
Edmundson asked that he be sentenced as a youthful offender because he had just turned 18 and he did not have any felony arrests.
"What about the words you said?" Allan asked Sales.
"I was on the streets my whole life," said Sales. "I guess that's how I expressed myself until I started reading the Bible."
Allan urged Sales to find the boys and tell them that it is wrong to use the racial slur.
Next time Sales hears someone utter the word, he should admonish that person, Allan urged.