World Cup play in underway with the host Brazil scoring a 3-1 come-from-behind victory Croatia in the opening match of the tournament.

Brazil had a disastrous start when defender Marcelo found his own net while trying to clear a low cross by Ivica Olic in the 11th minute, but Neymar then showed why the nation's high hopes are all pinned on him.

The 22-year-old forward equalized in the 29th by clearing a defender near midfield before making a run toward the edge of the area and firing a low shot that hit the post before going in.

The showcase stadium that was beset by construction delays put on a shiny appearance for the opening ceremony and the kick off match. 

But the day was not without some of the problems that have plagued the lead up to the event. 

Brazilian police have clashed with anti-World Cup protesters trying to block part of the main highway leading to the stadium.

Images aired by the Globo TV network showed riot police using tear gas and rubber truncheons to disperse about 50 demonstrators who tried to block the Radial Leste highway.