The move that could well become one of the defining moments of the season came with four laps to go.
Norris had driven well on an inverted strategy from seventh on the grid to contest the final podium place with Antonelli and Piastri.
Norris had been within a second of Piastri, and with use of the DRS overtaking aid, for several laps and on lap 66 dived down the inside of his team-mate at the hairpin to take fourth place.
Piastri got the cut-back on Norris out of the corner and they drove down the back straight towards the final chicane side by side, Piastri on the inside.
Approaching the last corner, Norris braked earlier than Piastri, with the aim of getting a quicker run through the chicane and attempting a move into the first corner.
But Piastri held his line on the pit straight, and as Norris closed on him, his right front wheel and front wing ran into the back of the rival McLaren.
Norris retired on the spot with broken front suspension but Piastri was able to continue as the safety car came out, and led the pack to the chequered flag.
Norris’ engineer Will Joseph asked Norris over the radio whether he was all right and the Briton replied: “Yep, I’m sorry. It’s all my bad, all my fault. Unlucky, sorry. Stupid from me.”
The move had echoes of a similar incident between McLaren team-mates in Canada, when Lewis Hamilton and Jenson Button collided in more or less the same place at this race in 2011.
But the incidents were different. In 2011, Hamilton had some of his car alongside Button, who moved over slightly. This time, Norris did not have space to edge alongside and appeared to misjudge the manoeuvre.
With 14 races to go, it is far from a fatal blow to Norris’ title hopes, but it makes his life much harder against a team-mate who on balance has had the edge on him so far this season.
More to follow
