The Ferrari driver had locked out the front row with teammate Carlos Sainz, leaving world champion Max Verstappen third on the grid and Perez in fifth.
But the fierce power of the Red Bull dragged both cars past Sainz off the line and they reeled Leclerc in, as they went three abreast into Turn 1 at the end of F1's longest opening straight.
Verstappen took the inside line, making him the favourite for the lead, with Leclerc squeezed in the middle and unable to avoid contact with Perez on his left flank.
The Mexican's car popped into the air as he slid wide, leaving Leclerc scrambling across the grass with damage to his front wing.
A hectic opening lap in Mexico City 😲 pic.twitter.com/lQE3LptAw1
— Sky Sports F1 (@SkySportsF1) October 29, 2023
Perez looked down and out and, despite limping back to the pits with a big hole in his sidepod, so it proved even after Red Bull mechanics attempted to get him back out - albeit for only a parade run in front of his adoring fans at Autodromo Hermanos Rodriguez.
Leclerc continued in second place with the end-plate of his front wing dangling off. It was jettisoned a few laps later without a black-and-white flag compelling him to pit for its removal, although its collection prompted a short virtual safety car and stewards said they would investigate that part of the incident post-race.
"I had a tremendous start, the gap was there," Perez said. "I went for it, I wasn't expecting Charles in the middle to brake as late, simply there was no room for three cars. It was a total racing incident."
Verstappen strolled into the lead and pitted early, along with Lewis Hamilton who performed the undercut on Sainz in a fight for third place.
However, a red flag stopped the race on Lap 35 after Kevin Magnussen crashed out at Turn 9.
Verstappen cruised off into the distance from the standing restart as Hamilton, after swapping to Medium tyres, overtook Leclerc for second place.
The Brit pulled out a five-second gap as the more durable Hard tyres began to gain an advantage over his declining rubber in the final 15 laps.
However, Hamilton held out to follow Verstappen through at the chequered flag. Leclerc and Sainz rounded off the top four in front of Lando Norris, the McLaren driver continuing his fantastic end to the campaign with a superb drive from 17th on the grid to fifth.