Uruguay had done well in defence to nullify the threat of Brazil in attack, but their good work was undone on 74 minutes.
After a long ball had not been dealt with properly, Laxalt was judged to have brought down Richarlison as he caught him while attempting to clear the ball.
Uruguay's players were certain that it shouldn't be given as a fould, but referee Craig Pawson stuck to his decision.
When tensions died dow, captain Neymar stepped up to take the kick and sent the goalkeeper the wrong way, stroking the ball in to the right corner of the net.