The Paris Saint-Germain forward struck twice in a thrilling last-16 clash to send Les Bleus into the World Cup quarter-finals with a 4-3 win, becoming the first teenager to score more than once in a World Cup game since Pele in 1958.
His pace was a constant threat to Jorge Sampaoli's side throughout and a surging 70-yard burst in the first half resulted in a penalty, which was converted by Antoine Griezmann.
Thauvin - who replaced Mbappe in the 89th minute for his first appearance at Russia 2018 - says the 19-year-old's brilliance could scarcely be believed by those on the sidelines.
"Honestly, sitting on the bench, we were a bit shocked because it was unbelievable," he said.
"He left from our side, from midfield, he ran 50 meters to obtain a penalty. It's incredible, it’s incredible.
"At some points, I was wondering: 'Is he riding a scooter on the pitch?'
"So, it's incredible. He has awesome qualities, and he uses them for the benefit of the team, and we celebrate them."