Ferrari's Vettel finished second.
"We saw what happened a year ago with the red vehicle behind", he said.
"It's a fantastic title number and I'm so happy for Lewis and the team, but it's bittersweet - we have had a very bad race and we need to understand it". "I'm not superstitious or any of this bullshit, but. the car's cursed. I'm going to fighting to at least gain a position but of course I'm aware of the Bulls up ahead".
"I still wasn't convinced as it wasn't the cleanest but putting it on pole, I can relax now because I'm tripping major nutsack right now!"
The 1-2 start will be the first for Red Bull since the start of the hybrid engine era in 2014.
Verstappen cut a markedly less enthusiastic figure after the session. "The pace is definitely going to be better than we have now in terms of power". "In the end we were not good enough".
Lewis Hamilton claimed his fifth drivers' world championship on Sunday to draw level with Juan Manuel Fangio in the Formula One record books when he finished fourth behind a victorious Max Verstappen in the Mexican Grand Prix.
The Briton hailed his team for turning around his auto after a deeply uncompetitive showing during Friday practice.
He said: "Helpless I think is the best word".
"We had a hard day yesterday and today was a big improvement".More news: Suspected mail bomber seen smiling in court appearance
"Yesterday we were much further back and we weren't expecting to be as high as we got". It's been a while since I've had a good weekend in general.
He had been all smiles on Saturday after pipping Verstappen to pole position but made a poor start on Sunday with wheelspin dropping him to third.
"He wanted to get out of the circuit pretty quickly as you can imagine, so we'll speak a bit later when things have calmed down".
"It was a mighty last lap from him".
Home favourite Sergio Perez, whose laps through the unique stadium section were greeted with rockstar-like cheers, could manage only 13th, two places off Esteban Ocon in the sister Force India.
It meant the battle to avoid elimination came to a head after the chequered flag, with the entire midfield taking to the track at once in a bid to make it through to Q2.
Stoffel Vandoorne split the two Haas drivers as he also delivered a competitive showing despite dropping out - missing out on Q2 alongside Alonso by a little over 0.1s - while Lance Stroll and Sergey Sirotkin were the slowest two cars as Williams struggled. Kevin Magnussen (Haas); 3 laps: 16. Marcus Ericsson (Sauber), 10.