Antonio Giovinazzi has criticised Nikita Mazepin for disrespectful driving after having his final qualifying lap ruined by the Haas rookie at Imola.
At the end of Q1, the opening qualifying segment, Mazepin followed Giovinazzi down the main straight and used the Alfa Romeo's slipstream to overtake into Turn 1. That immediately compromised Giovinazzi's lap, and Mazepin soon made a mistake that ruined his own effort.
After the incident, a radio message of Giovinazzi was broadcast, with the Italian saying: "What is Mazepin doing, honestly?"
Speaking after the session, Giovinazzi said Mazepin ignored a gentlemen's agreement which exists between all drivers.
"It's quite clear," Giovinazzi said.
"We respect each other on this, starting the lap, and he didn't respect this. This is really not correct for a qualifying lap. I didn't make my last lap."
Mazepin defended himself in his own post-session media interviews, saying the situation at the end of qualifying means drivers have to put their own interests ahead of any etiquette.
"In F1 it is a bit difficult as there's 20 cars, obviously, in segment one, which is where we are," Mazepin said.
"Everyone is going out at the same time, and the track is just not big enough for all of us.
"We had this chat about the gentlemen's agreement, and obviously I didn't have a problem with that. But when there is three seconds on the clock, it is either you go or you have to box, and you're going across the start/finish first.
"So I don't think there's an issue with it. I'm here to do my laps, and, you know, we are all in the same world."
Haas boss Guenther Steiner defended the team's timing of Mazepin's final lap, pointing out that Giovinazzi could have managed his out-lap differently if he wanted to avoid being overtaken at the start of his timed attempt.
"We are not doing it on purpose, but it is getting very busy at the end of the session in sessions like this," Steiner said. "So you just have to go and hope for the best, because if you don't go, you lose the lap anyway.
"I don't think you can call this a gentlemen's agreement because then again Antonio could have gone faster as well; he knew that Nikita was behind him and needed to make the chequered flag or [could] miss the chequered flag, so it's unfortunate, no-one's doing this on purpose or anything, but it's racing and if you are here racing, you need to try to take every opportunity you have got."