Marcelo has hailed his Brazil teammates and home supporters for staying behind him following an early setback in the tournament's opening game.
The full-back put the ball into his own net early on to give Croatia the lead, but the hosts bounced back to eventually secure a 3-1 victory.
"The first thing I thought was just to stay calm and not make it worse for the team," Marcelo told FIFA.com when asked about his reaction to the 11th-minute own goal.
"If I'd let my head drop, I might have ended up making life even more difficult for us. That was the first thing I had to make sure I didn't do.
"The fans were right behind me after I scored the own goal and they were chanting my name. My teammates also came up to me and that helped me clear my head straight away. I got back into the game immediately."
The victory ensures that Brazil top Group A after their opening game, with Mexico and Cameroon still to meet later today.