The choice of third-grader Julia Lira for the drum queen post that is usually occupied by scantily clad, high-heeled models and buxom TV stars, sparked controversy and a legal challenge by a child protection agency who said she was in risk of being sexually exploited.

The final word was left to a family court judge, who decided to disregard the agency´s appeal and allowed the girl to join the show.

The youngest Carnival queen hesitated to enter at the Sambadrome in the first hours after seeing the crowd, but a little later she was already comfortable and dancing in front of roughly 300 musicians.

Lira was cheered by thousands of fans and celebrities including pop diva Madonna, who watched the parades from up close at the governor´s special viewing box.

The 51-year-old pop star went to the Sambadrome with her children and Jesus Luz, her 22-year-old Brazilian boyfriend.

Madonna arrived in Rio last week for the Carnival and has been pictured at restaurants and concerts around the town since then. The celebrity also took a short trip to the business capital Sao Paulo to raise funds with which she hopes to establish social projects in Brazil.