He made a move round the outside of his team-mate and the Ferrari driver, and seemed to have his nose in front, before tagging Leclerc's front wing and hurtling off the Autodromo Hermanos Rodriguez track.
Now, Perez has suggested that the incident wasn't anybody's fault, and that his desire to chase a dream victory in front of his adoring fans may have caused the incident.
"Yes, there were three of us in T1, and with these very wide cars it was complicated to get through," he told Canal+.
"I took a risk and it didn't pay off. It's a shame that it happened here in front of my home crowd. It's the worst thing that could've happened, I didn't think Leclerc would brake so late."
"I had a very good start. I was just thinking about winning. I didn't want to be on the podium. I have been on the podium for two years in a row and the truth is, I was only thinking about winning today no matter what. I saw the opportunity and went for it.
"In retrospect, I risked a lot. But if he had made it, he would come out of the first corner in first place."