Norris & Piastri collide as Russell wins in Canada

Lando Norris walks away from his damaged McLaren after after colliding with Oscar Piastri

Title rivals and McLaren team-mates Lando Norris and Oscar Piastri came to blows for the first time as the Briton appeared to misjudge a passing attempt in the Canadian Grand Prix.

Norris hit the back of Piastri's car on the pit straight with four laps to go as George Russell took Mercedes' first victory of the season with a controlled drive.

Norris, who had been attempting to pass Piastri for fourth place, told his team it was "all my bad" and that it was "stupid of me".

Norris' car retired on the spot with front suspension damage and the race finished under the safety car with Piastri in fourth place behind Russell, Red Bull's Max Verstappen and Mercedes' Kimi Antonelli.

Red Bull lodged a protest, claiming that Russell drove erratically behind the safety car, but it was rejected by the stewards.

Piastri's championship lead over Norris increased to 22 points, with Verstappen 21 adrift of the Briton.

The move that could well become one of the defining moments of the season came at the start of lap 67 of the 70-lap race.

Norris had driven well on an inverted strategy, starting on the hard tyre from seventh on the grid and running long to his first pit stop, to come into contention for 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.

Impressive Russell takes comfortable win

Russell celebrates his first grand prix victory since Las Vegas in November

The drama between the title contenders took the focus off an impressive performance from Russell and Mercedes as they converted his superb pole lap on Saturday into a comfortable victory.

The Briton made a good start and was under no threat from Verstappen into the first corner, and from there he controlled the race.

The largest the gap got was 5.2 seconds shortly before Verstappen made his second pit stop. The world champion narrowed that margin in the final stint but even when traffic in the final stages of the race reduced Russell's lead to a second, he was able to pull away again.

Antonelli's race was much more pressured. He passed Piastri with excellent race craft through the first few corners, which gave him the inside line for Turn Three.

Piastri dropped back to a couple of seconds behind during the first stint, but McLaren ran him slightly longer than the Italian into both his pit stops, which gave him a tyre advantage for the final stint.

Piastri closed on to Antonelli's tail with 17 laps to go but their battle allowed Norris to close up, which meant the Australian had to turn his attentions to his team-mate until their collision.

Antonelli, at 18 years and 294 days, is the third-youngest driver to achieve an F1 podium, behind Max Verstappen and Lance Stroll.

Behind the top four, Ferrari were the slowest of the top four teams, Charles Leclerc taking fifth ahead of Lewis Hamilton, whose race was compromised by hitting a groundhog on lap 13, which damaged his car's floor and cost some downforce.

Leclerc spent much of the race complaining about the team's strategy choices.

Like Norris, he started on the hard tyre and ran a long first stint. He told the team he wanted to run much longer and try a one-stop, but instead they pitted him on lap 28 - one before Norris - and fitted another set of hards, which meant he was now locked into a two-stop.

Behind the Ferraris, Fernando Alonso took points for Aston Martin for the second race in a row with seventh place after his excellent sixth place on the grid in qualifying.

The veteran Spaniard led home Sauber's Nico Hulkenberg, while Haas driver Esteban Ocon and Williams' Carlos Sainz proved a one-stop was possible in ninth and 10th.

• Drivers' championship standings

• Constructors' championship standings

What's next?

It's back to Europe for the Austrian Grand Prix at the Red Bull Ring, from from 27-29 June. Russell won there last year after Norris and Verstappen collided while contesting the lead.