Australian Oscar Piastri has gone from fastest in Mexico City to out in the first part of qualifying.

The McLaren driver never looked comfortable in Q1 at qualifying for the Mexico City Grand Prix, being knocked out after only managing 17th fastest.

It was the polar opposite of just a few hours earlier when Piastri was the fastest driver in the final practice session.

Red Bull and hometown favourite Sergio Perez also struggled despite the backing of a raucous crowd, qualifying 18th fastest.

Piastri had three laps during the qualifying session, making a mistake early in his first lap which cost him time.

He had his second lap deleted due to exceeding track limits — although that time would not have been good enough to move to Q2 anyway. 

With the pressure on and on a set of tyres he had just used, Piastri could not hook up the lap he needed.

Piastri said he made a mistake on that final lap which cost him about one second.

"My lap was easily going to be enough, so it's very frustrating to make that mistake,' he said.

"I made a very poor mistake, and that was it."

Ferrari's Carlos Sainz took pole with a sensational final lap in qualifing, two tenths ahead of Red Bull's Max Verstappen. 

McLaren's Lando Norris, who was fastest in Q1 and Q2, snatched third from the other Ferrari of Charles Leclerc by five-thousandths of a season.