Germany boss Low took Gotze aside during the break of extra-time and the 22-year-old, who had come off the bench, scored a brilliant volley to break Argentinian hearts in the Maracana.
The 1-0 win saw Germany crowned world champions for a fourth time and Low said of Gotze: "He is a miracle boy, a boy wonder - he can play in any position. I know he is always able to decide a match and he's scored a great winner.
"I said to him, 'okay shown to the world that you are better than Messi and that you can decide the World Cup'.
"I had a good feeling about him."
Gotze hailed the World Cup victory as "absolutely sensational".
Gotze, who had had a difficult season at Bayern Munich, said: "It is an unbelievable feeling, you just score that goal and you just don't really know what's happening.
"It's indescribable, you are having a party with the team, with the country, the dream has become a reality. It is absolutely sensational."
Gotze, who began the World Cup in Germany's starting line-up before being dropped to the bench, added: "It hasn't been an easy year for me and it wasn't an easy tournament. I owe a lot to my family, my girlfriend, and my friends who have always believed in me.
"It was not been easy but I simply kept on training with the team and every single player deserves to be named - we deserved this trophy."
Low also expressed his pride at Germany becoming the first country to win a World Cup in north, central or south America.
He added: "This is the result of many years' work beginning with Jurgen Klinsmann and we continued that.
"Over the years we have been able to improve our performance and it has been 10 years of tough preparation.
"The players have a marvellous technical ability and the will-power to carry it out.
"We are proud to win it here in Brazil, the footballing country par excellence, and to be the first European team to win in Latin America."