Formula 1 driver Jenson Button ahead of this weekend's Singapore Grand Prix heaped praise on Lewis Hamilton as one of the "quickest ever" drivers in the history of F1.
The pair were teammates for three seasons at team McLaren before Hamilton joined Mercedes in a move which, although considered a gamble at the time, has proved to be a career-defining masterstroke.
"Lewis is extremely fast over one lap, probably one of the quickest ever," Button was quoted as saying on Sky Sports on Wednesday.
"He has used that massively to his advantage this year. It puts him on pole position and then because of the way the cars are and the way he can control the situation, Nico is never going past," he said.
Button is one of five world champions in the field but, through no fault of his own, has been reduced to backmarker status this term in a McLaren car crippled by an underpowered Honda engine.
"Lewis goes around at a certain speed and then two laps before the pit stop he pushes which means Nico can't have a go at him - he can't undercut him, he can't overcut him, he can't do anything," he said.
"Lewis has definitely improved when it comes to thinking about his race. Last year he had reliability issues and made mistakes, which we all do, and still won the championship. This year, he is not making mistakes, and the team isn't making mistakes, and he is walking away with it," Button said.