Monday will be the anniversary of Ferrari's last Formula One victory and Leclerc, who was on provisional pole until Norris put in a storming late lap, said it would mean a lot to win.
Juan Pablo Montoya spun out team mate Scott Pruett late in the race before claiming his first Nascar victory.
Norris had shown his pace in final practice when he became the third different driver to top the timesheets in the three sessions, punching out an impressive lap 0.345 faster than anyone else.
Red Bull closed the gap to champions Mercedes in the constructors' standings to one point.
Red Bull's double World champion Max Verstappen won the Mexico City Grand Prix on Sunday to set a Formula One record of 14 victories from a single season, as well as the most points scored.
Red Bull's double World champion Max Verstappen swept to pole position at the Mexico City Grand Prix on Saturday with his sights set on a record 14th victory of the season.
The world's fastest man Usain Bolt took the record-breaking Genbeta electric car for a spin ahead of the first race of the Formula E season in Mexico City.
Norris last led the standings in April, a gap of 189 days, and had not won a race since Hungary in early August. Sunday was his sixth victory of the season, one less than Piastri, and career 10th.
'I'm so grateful for everyone who helped me be here, to raise the bar and lift the cup'
Charles Leclerc swept to pole position for the Mexico City Formula One Grand Prix on Saturday with Carlos Sainz qualifying second in a surprise Ferrari front-row lockout.
Daniel Ricciardo dashed Red Bull team mate Max Verstappen's hopes of becoming Formula One's youngest ever pole-sitter on Saturday while championship leader Lewis Hamilton qualified third for Mercedes at the Mexican Grand Prix. Hamilton, who need only finish seventh on Sunday to secure his fifth title with two races to spare, will have Ferrari rival Sebastian Vettel alongside on the second row.
Max Verstappen became the first Formula One driver to take 16 victories in a season
Sebastian Vettel's expletive-laden radio rants betray his frustration at Ferrari's fading form, according to his former Red Bull team mate Daniel Ricciardo and predecessor Fernando Alonso.
India has been dropped as previously announced, with hopes for a comeback in 2015, while Austria is due to make a return after an 11-year break with a race at Spielberg on June 22.
Fresh from his 50th Formula One win, triple world champion Lewis Hamilton remains convinced anything is possible in the title race even if he could lose his crown as early as Sunday.
'I want everything recyclable, down to deodorant, toothbrush, all these kind of things. I'm trying to make as much change as I can in my personal space'
Nico Rosberg said it was 'business as usual' after beating Mercedes team mate Lewis Hamilton to pole position for the fourth race in a row on Saturday in the first Formula One qualifying held in Mexico since 1992
Some Formula One drivers never experience the pride and passion of racing in a home grand prix, their countries unlikely ever to appear on the calendar, but Mexican Sergio Perez will not be one of them after this weekend.
Lewis Hamilton became Britain's first four-times Formula One world champion on Sunday after fighting back from last place following an opening-lap collision with arch-rival Sebastian Vettel at the Mexican Grand Prix.
