Having overtaken Perez on track in the first stint, Leclerc lost out to the Red Bull driver through the pit stop phase.
The pair made contact at Turn 4 and then at Turn 6 - on both occasions Leclerc was pushed into the gravel, resulting in Perez receiving two separate five-second time penalties.
“We were strong all the race with the race pace but we didn't have the tyre advantage of the reverse strategy so it was very, very difficult to overtake,” Leclerc told Sky Sports F1. “Every opportunity that I could see I was going for it.
“It didn’t work out today. I was pretty angry in the car because I felt like I had no space. I know the overtakes were quite optimistic but on the other hand I had to do it if I wanted to make it work. There was no space on the outside, on the exit of the corner, but it’s life.”
Not only was Leclerc unable to overtake Perez, but he was also stuck behind McLaren’s Daniel Ricciardo.
Ferrari ordered Leclerc to let Sainz through for seventh on track, with the Spaniard making a move in the closing laps on Ricciardo for sixth, before moving up to fifth after Perez’s time penalties.
“I felt like there was an opportunity to get past [Ricciardo] at one point because I was very close every lap,” Leclerc added. “They asked me to swap the cars because he had the tyre advantage with the reverse strategy so I did.”