Daniil Kvyat has peeled back the curtain on a series of "heated moments" shared with Carlos Sainz during their time in the Red Bull junior program.
The duo ascended to F1 in 2014 and 2015, emerging from years under the Red Bull racing umbrella.
Their rivalry, however, predates their F1 days, with competitive clashes in various junior formulae, including Sainz clinching the Formula Renault 2.0 NEC title over Kvyat in 2011.
As they climbed the ranks within the Red Bull set-up, Kvyat, in an interview with Formula1.com, spilled the beans on the intensity that occasionally sparked between them.
Kyvat: Our fathers had to intervene
“Today me and Carlos are really good friends, but when we were team mates there were some heated moments,” says Kvyat. “We travelled a lot together, we had some contact on the track, and sometimes even our fathers had to intervene and say, ‘Hey, guys, calm down!’
“During the GP3 season, Helmut told us, ‘OK, an F1 seat is on the table, so whoever does best will probably get it’, and that’s when it started to be very serious. I remember the round in Belgium, where we started first and second, almost tied on points, and I had to get that win. I won it, Carlos had a crash and I got a big lead in the points.
“There was another European F3 championship at the time, with a bit of a different car. Helmut wanted me to also do some races in that series, to do well in both cars, and I started winning there as well. I remember a race at the Red Bull Ring and it was close to Helmut, so he came to say hi, and I did three pole positions out of three, so that was a very important step.
“Then Carlos felt it and he said he’d do the World Series by Renault, just to show Helmut that he could do well in both cars, only that in his case it wasn’t going as well. So, more things were in my favour, I won the GP3 title and I was offered the Toro Rosso contract for 2014 before the last race. It felt like a huge achievement at the time, putting my signature on it.”