Six-time Formula One world champion Lewis Hamilton is on his way to becoming the greatest of all time, according to former title rival Nico Rosberg.
Hamilton was crowned champion on Sunday after finishing second to Mercedes team-mate Valtteri Bottas at the United States Grand Prix in Austin.
The Briton, who only needed a top-eight finish to secure the title, qualified in fifth place but was leading the race on lap 52 only for Bottas to make the most of fresher tyres and overtake him.
Hamilton has won three drivers' championships in a row and five of the past six, his run broken by former Mercedes team-mate Rosberg's triumph in 2016.
He is also now clear of Juan Manuel Fangio in the all-time standings and just one behind Michael Schumacher's record haul of seven titles.
Rosberg, who retired after being crowned champion three years ago, thinks the 34-year-old Hamilton could go on to become regarded as the best in the sport's history.
Writing on Twitter, he said: "Karting together who would have thought that we'd both be F1 world champion one day.
"And you? You've achieved it for the sixth time – on your way to becoming the GOAT. Impressive!
"My greatest respect – enjoy these moments and celebrate. Well deserved."
Appearing on Sky Sports, Rosberg went on to praise Hamilton for adopting a one-stop strategy that almost saw him claim an unlikely race victory.
"I need to really say – we saw all of Lewis' class today," he said. "He took the strategy into his own hands and made it a better strategy than the team gave him.
"Of course, it's a completely deserved sixth title, in amazing fashion."