McLaren's Lando Norris beat Max Verstappen to win a gripping Sao Paulo Grand Prix in which new world champion Kimi Antonelli and Mercedes team-mate George Russell both made critical mistakes in difficult conditions.
Norris, who started from pole, lost the lead to Antonelli at the start and dropped back when the track was wet.
But an earlier pit stop for dry-weather tyres put Norris on Antonelli's tail and the Italian spun away the lead at the first corner.
After reclaiming the lead, Norris dominated through a late shower of rain which required a switch back to wet-weather tyres to take his first win since the Dutch Grand Prix at the end of August.
A few laps before Antonelli lost the lead, Russell, who started seventh, spun exiting the pits and lost 15 to 20 seconds after working his way back into podium contention.
Despite their travails, Russell and Antonelli finished fourth and fifth to clinch the constructors' championship for Mercedes a week after the Italian had tied up the drivers' title.
Norris had too much pace for Verstappen whether the track was dry or wet and stamped his authority on the race.
But the Dutchman put in another supreme drive in changeable conditions in Interlagos to take second after starting in 21st place.
The key stories of the race were:
An accomplished performance from Norris in a revived McLaren to take his first win for more than two months
A superb comeback from Verstappen from an engine penalty
A difficult day for both Mercedes, notwithstanding the greater glory of the constructors' win, and Ferrari in the tricky conditions
Norris had started from his first pole position since the Spanish Grand Prix in September, but lost first place immediately after Antonelli, alongside him on the front row, leapt into the lead.
The new world champion pulled away to build a five-second lead in 10 laps as he began to look as if he might crown his achievement with a win at the first attempt.
Antonelli's lead was more than eight seconds by lap 13 but the track was drying and three laps later Norris came in for dry-weather slick tyres.
The Italian followed him in a lap later but Norris had gained so much time with his earlier stop that he was on the Mercedes' gearbox when it rejoined.
Antonelli defended for a couple of laps but he was complaining over the radio that the car felt strange under acceleration, and on lap 20 he lost control on the entry to Turn One, spinning and handing the lead to Norris.
That left Norris three seconds ahead of Hadjar with Verstappen now close behind Antonelli, who ran wide again at Turn One four laps later and handed third place to the Dutchman.
Hadjar had every bit as much pace as Verstappen, but was not as consistent and made too many mistakes, and within 10 laps the team leader was on the Frenchman's tail.
Red Bull ordered Hadjar to let Verstappen by on lap 39 in the hope that the four-time champion could close on Norris.
But the Briton had too much pace and held off Verstappen, switching to another set of soft tyres before needing intermediates when the rain came down increasingly heavily in the final 10 laps.
Verstappen had made speedy progress up from his position at the back.
Initially, Lewis Hamilton, who had started alongside the Red Bull, progressed faster, and was ninth by lap two, but Verstappen soon got into his stride and was passed the Ferrari within a further two laps and continued his forward progress.
By lap 10, Verstappen was up to a remarkable sixth place and right behind the Racing Bulls of Liam Lawson, with Hadjar ahead chasing Russell, who by then was up to third after starting seventh.
But Russell dashed his own hopes when he stopped on lap 16, at the same time as Norris, and spun in the pit lane exit which mirrors on the inside of the track the run through the Senna S first two corners.
Russell was broadside in the pit lane as rivals squeezed past him left and right as he manoeuvred his way straight again and rejoined the race, now down in 10th place.
After that, he drove well with strong pace to put himself back in contention and a fourth place was a strong result in the circumstances.
He had more pace than Antonelli in the closing laps and the team ordered them to swap positions as they sealed their ninth constructors' title, and first since 2021.
McLaren's Oscar Piastri was sixth, nowhere near Norris' pace, while Ferrari's Charles Leclerc took seventh after a topsy-turvy race ahead of Lawson and Hamilton.
Audi's Nico Hulkenberg took the final point for 10th place.
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