Sebastien de la Cruz has one message for the people who posted racist rants about him after the boy performed the national anthem at an NBA finals game dressed in a San Antonio Spurs-themed black and silver mariachi outfit.

"To the people that do have hatred in their hearts, I just want to tell them that they should think before they say things," the 11-year-old told " Good Morning America."

Sebastien is a San Antonio, Texas, native who, like 63 percent of the population in that city, according to the U.S. Census, is of Hispanic origin.

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When he was invited to sing "The Star-Spangled Banner" before Game 3 of the NBA finals Tuesday night, he donned his mariachi outfit and wowed the crowd inside the San Antonio Spurs' AT&T center with his rendition of the national anthem.

Online, however, Sebastien was torn apart by Twitter users who erupted in outrage about the sight of a Mexican-American boy singing the national anthem dressed in a traditional Mexican outfit.

"This kid is Mexican why is he singing the national anthem #yournotamerican #gohome," wrote on user, @Gordon_Bombay24.

"All I was thinking about was why would people talk like that about me," Sebastien said of such responses.

The San Antonio Spurs, playing against the Miami Heat in the finals, had a different reaction, however, and invited Sebastien back to sing the national anthem again before Thursday night's Game 4 of the series.

"He's a class act," Spurs' coach Gregg Popovich said. "He makes you feel that the future can be very bright."

Sebastien returned dressed in his same mariachi outfit and was introduced by San Antonio Mayor Julian Castro, himself a San Antonio native of Hispanic descent.

His encore sparked a different kind of reaction from one tweeter: "Hey, racists, how does it feel to be schooled by this awesome … Nat'l Anthem singer?"

Of being asked back to sing, "I was overjoyed," Sebastien said. "I was super-happy. I actually started to shake."