2009 world champion Jenson Button says he was inspired to produce the best performances of his Formula One career when racing against Lewis Hamilton at McLaren.
Button and Hamilton were partnered at McLaren between 2010 and 2012, with Button managing to out-score his fellow countryman on points across their three-year spell as teammates, a feat he shares with only one other driver, after Nico Rosberg pipped Hamilton to the title in 2016.
The 37-year-old, who retired from F1 at the end of the 2016 campaign -- barring a one-off appearance at last year's Monaco Grand Prix as stand-in for Fernando Alonso -- admits that while he could match Hamilton in race-trim, his former teammate held all the aces over one lap.
"He is unbelievably quick and, over one lap, he is the quickest guy I think that has ever driven a Formula One car," Button told Sky Sports. "In a race, I could challenge him, and we could race for wins. Over those three years we won a lot and some of the races I did win were the best races in my career, because I had to beat Lewis to achieve them.
"Our relationship was interesting. Because I came from Brawn, where I won the world championship in 2009 -- and he won the previous world championship in 2008, with McLaren. I moved to his team, if you like, so I walked in the door looking for that challenge of racing against Lewis Hamilton.
"Both British, racing for a British team, both world champions, fresh new world champions, so it put a lot of pressure on us and that made it fun, I really enjoyed that challenge."
In his autobiography 'Life to the Limit', Button revealed there was the odd moment of friction between the pair at the Woking-based outfit, particularly following a tense duel during the 2010 Turkish Grand Prix.
"Did he like being beaten by his teammate? Probably not, but he's a competitor and I'm sure that like me he relished the challenge. That's why we do what we do. Personally, he was fine with me, but you could just tell he was a little bit peeved.
"I don't think that I was to his taste, if I'm honest. And things took a bit of a turn for the worse in Turkey, when we almost had a collision that led to a minor falling-out between us."
Button is set to make his full-time racing return by contesting this year's Super GT championship in Japan with Honda, following his sabbatical year in 2017.