The Brazilian driver, who won titles in 1981, 1983 and 1987, said it is “very difficult to make a direct comparison between two drivers if they are not on the same team” but believes the Dutch driver would come out on top in a side-by-side challenge.
Piquet also questioned the ability of Hamilton’s teammate Valtteri Bottas, saying: “It’s not that Hamilton isn’t good. But he has an inferior driver by his side and the previous one [Nico Rosberg] was even worse.”
His son, former Formula E champion Nelson Piquet Jr, also backed Verstappen, saying he is “coming with a knife between his teeth.”
The pair spoke after Verstappen narrowly missed out on victory at the Bahrain Grand Prix on Sunday having been forced to give back first place to Hamilton after passing him while off the track.
Piquet told Motorsport.com: “First of all, we have to consider that F1 is a category with different cars, so it’s very difficult to make a direct comparison between two drivers if they are not on the same team. But if Max were driving for Mercedes, I’m sure that he would smash Hamilton.
“Max is more aggressive. He may make mistakes more frequently due to this aggressiveness, but in my opinion he’s better than Hamilton. Things are too easy for Hamilton to win it all with Bottas by his side as a second driver.
“It’s a little bit like Mansell and myself in Williams, with the other drivers far behind. I won the 1987 championship, and I wasn’t driving like before, because I had the accident at the beginning of the year and had field depth problems. But I won that championship, with a bit of luck. I should have won in 1986, but won in 1987.
“But it was so easy. The car was far better than the others. And Mercedes is far better than the others for the past years.
“It’s not that Hamilton isn’t good. But he has an inferior driver by his side and the previous one [Rosberg] was even worse. He [Rosberg] won because it was a year where Hamilton had crashes and DNFs.”
Piquet Jr, who also had a brief spell in F1, driving for Renault alongside Fernando Alonso in 2008-09 added: “I think we have to consider two things: Lewis’ experience and Max’s desire. Lewis has been in F1 for 15 seasons and I think that, little by little, you start to lose that desire. On the other hand, Max is coming with a knife between his teeth.
“Lewis has already won seven championships, so he comes with another type of ‘fire’. And that can make a difference.
“I like to compare Max with a MMA fighter, coming ready to face any challenge. It’s different from Lewis, that already won championships and so on.
“Lewis’ experience will help in some areas, but Max’s willingness and aggressiveness is bigger.”