Charles Leclerc has revealed the "four or five years" of "conflicts" that led to his early rivalry with reigning F1 world champion Max Verstappen.
The Ferrari driver was one of Verstappen's primary adversaries during their years in karting, with the two drivers often at the sharp end of the grid.
A video from one of their races in which they clashed has gone viral, showing the frosty nature of their rivalry at the time.
Although Leclerc and Verstappen are title rivals this year, both drivers have so far shown great respect and shared warm and friendly conversations in parc fermé.
But recounting their days in karting, Monégasque Leclerc explained: "In karting, we had a lot of conflicts. Yeah, really a lot!
"We've been racing together for like four or five years and every race we would be fighting for wins and obviously loads of things happened in karting.
"We were also young, crazy and yeah, we hated each other at that moment. But now we grew, the experience is more and obviously, also we have both realised our dream to be fighting for F1 so the relationship has changed since then.
"But now I think we both look back to these years with a smile on our faces. This video is viral, I've seen it so many times now on social media. But yeah, they were very good years for sure."
Leclerc hopes for season-long tussle
Leclerc holds a 19-point advantage in the race for the F1 title after Red Bull driver Verstappen cut the gap with his third victory of the season in Miami last time out.
Asked how he feels to be battling his former rival for the title, Leclerc replied: "I mean, it feels good. We were both dreaming of one day arriving to Formula 1 and now it's the case and we're also fighting for the championship.
"So yeah, it's really cool. I like to fight with Max, it's always on the limit. And I really enjoy it for now.
"I hope it can stay like this for the rest of the season and hopefully we'll be able also to improve the car throughout the season to stay with them for the fight in the Championship."