After driving into opening practice for Aston Martin on Friday, de Vries was drafted for FP3 by Williams on Saturday, when Alex Albon fell ill and was diagnosed with appendicitis.
The rookie qualified 13th and moved up five places on the grid thanks to penalties for other drivers to start eighth.
He eventually finished the race in ninth and scored two points on his debut.
Wolff said the result was what De Vries deserved after such a strong show.
“He’s just a good young man,” Wolff said after the race. “Not only is he fast, and he has shown that in the junior categories, but he is also intelligent and a good team player.
“And that’s why he deserved it today. I don’t think anyone else could have done better at what he did.
“You’re in an Aston Martin, you drive around with the rake. And then you get called up at the last minute in another car. You beat your teammate by a decent margin.
“You start eighth and you finish ninth. Niki [Lauda] would have taken off his hat as a driver.”
Although de Vries has been closely associated with Mercedes as a Formula E racer and F1 reserve, he is not officially in the manufacturer’s young driver program or under a management agreement like George Russell and Esteban Ocon are.
Nyck de Vries, Williams
Photo by: Williams
However, Mercedes is still very interested in its progress.
“Nyck was an official Mercedes driver until we retired from Formula E a few weeks ago,” Wolff said when asked about the relationship by TBEN.
“And he won the championship for us, our first world championship. So there is no more Mercedes driver.
“But we don’t have a management contract with him, we don’t influence his career, nor do we participate in his future earnings. We just know him very well.”
“And we’re judging him, and I think Nyck deserves to have a place in F1.”
Lewis Hamilton, who knows De Vries well through their Mercedes associations, congratulated him in parc ferme after the race at Monza.
“Incredibly happy for Nyck, I’m really proud of him,” said Hamilton when Motorsport.com asked him about the rookie’s performance.
“He’s such a good boy, a good person. And he’s been a good part of our team, he’s helped us and worked with us. That Nyck jumped in and finished in the top 10 I think that mega is for your first race.”