Former F1 world champion and American racing legend Mario Andretti believes Max Verstappen is a "very rare" talent.

Last weekend Verstappen became the youngest race winner in the history of the sport when, at just 18 years and 228 days, he held off Kimi Raikkonen to take victory at the Spanish Grand Prix. It was Verstappen's first race for the senior Red Bull team after being promoted from Toro Rosso, and Andretti believes he has proved himself as the real deal.

"He showed that spark repeatedly in the Toro Rosso last year once he reached F1," Andretti told ESPN. "He brought that Toro Rosso up to the next level just like Sebastian Vettel did. No one ever thought that a Toro Rosso would win, but Vettel did that in the most precarious conditions -- when there was a level playing field in the wet at Monza -- and he showed his capability then and Max is doing the same thing now.

"Talent at that level is very rare. He didn't just show it as a flash in the pan, he demonstrated his promise and that's why he was given the reward of going from the Toro Rosso to the Red Bull team.

"Of course [Red Bull young driver manager] Dr Helmut Marko now feels vindicated even though he was criticised for this early season move but it's obvious he made the right decision."

Andretti won in F1, IndyCar and NASCAR -- as well as a variety of other forms of motor sport during his career -- but at 18 years old was preparing his first car to race on dirt ovals. When it was put to Andretti that he was modifying a Hudson Hornet with his brother when he was Verstappen's age, Andretti said: "I know!

"From the inside, we are looking at him and saying 'Are you ever blessed, young man!' To have that chance at that age and to have been prepared so well, it's a golden opportunity but he earned it.

"He took advantage of everything that was at his disposal and he did a remarkable job."

Both Andretti's sons went on to race in motor sport and his grandson Marco Andretti is currently racing in IndyCar. The 1978 world champion said he could sympathise with the emotions Verstappen's father Jos must be feeling as he sees his son succeed in F1.

"I'm very happy for Jos because I'm in that position too and have been watching my kids compete and my grandkid now, so I know the satisfaction that brings to the family. I think that Max has cemented himself in the world of F1 and many of the experts are looking at him as a potential world champion, no doubt about it."