And the Ferrari driver was understandably angry because he had to let the Germans through as a faster driver.
In the end he ruined the race of Leclerc, as he came home only in fifth place, while Vettel stood on the podium.
Ferrari could not reach the pace of Mercedes, Lewis Hamilton won again ahead of teammate Valtteri Bottas.
And former Formula 1 World Champion Nico Rosberg was sorry for Leclerc.
"For Sebastian they got it right, but I feel for poor Charles Leclerc," he said.
"I do not know if he can return to Verstappen, but we hope this can be a really cool end to the race.
"Charles had the pace and was at the pace of the race.
"Sebastian was not faster when he passed him.
"It's really not a nice way to finish his race today."
After passing Vettel, Leclerc expressed his displeasure over the team radio, as he was much faster.
"I lose a lot of time," he said.
"I do not know if you want to know it or not."
However, Ferrari remained on the pitch and supported the four-time champion Vettel in front of his younger teammate.
Meanwhile, Hamilton was happy about the victory in the 1000th race of the F1.
"What a great result," he shouted after his 75th win.
"Thanks for all your hard work, let's push on."
For Hamilton, the Grand Prix of Azerbaijan is on the program on Sunday, April 28th.