Lewis Hamilton made it a magnificent record seven different winners in seven races this season on Sunday when he drove with speed and perfect control to win the Canadian Grand Prix.
The 28-year-old Briton produced a superbly judged race to wipe away all fears hanging over the event after a weekend of protests and police action in the city to seize his first win of the year.
Police reported the arrests of around 30 protesters in the hours before the race as Canadian students rallying for months over tuition hikes used the Formula One showpiece to highlight their cause.
Late Saturday, shield-wielding riot police had pushed back and chased hundreds of protesters amassed in the downtown shopping district, making 28 arrests.
The event itself passed off smoothly, with Hamilton's triumph coming five years to the day after he had claimed his maiden Formula One victory at the Circuit Gilles Villeneuve and his third win at what must be one of his favourite circuits.
It was his 18th career victory and it hoisted him back into serious contention for the drivers' title in this year of unexpected results and unpredictable racing.
He now leads the standings on 88 points ahead of Fernando Alonso on 86 and defending champion Sebastian Vettel on 85.
Frenchman Romain Grosjean of Lotus came home second after an equally well-judged race to finish ahead of third-placed Mexican Sergio Perez of Sauber.
Defending double world champion German Vettel of Red Bull finished fourth after a late second pit stop ahead of two-time champion Alonso of Ferrari and sixth-placed Nico Rosberg of Mercedes.
Australian Mark Webber was seventh in the second Red Bull ahead of Kimi Raikkonen, the 2007 champion, in the second Lotus, and Japanese Kamui Kobayashi of Sauber and Felipe Massa for Ferrari.
"Winner, winner! Well done you guys, thank you, thank you," said Hamilton on the team radio during his slowing down lap after finishing clear of Grosjean by more than 2.5 seconds.
Hamilton's McLaren team-mate, 2009 champion Jenson Button endured another troubled race and finished 16th while seven-times champion veteran Michael Schumacher was forced into early retirement by mechanical problems with his Mercedes.
At the start Vettel made a clean getaway from his 32nd pole position.
Hamilton and Alonso followed him in file order through the opening laps and the order remained unchanged until lap 16 when the defending champion made his first pit stop.
This gave Hamilton the lead and he produced a turn of speed in the clean air to make sure that when he came in two laps later he remained in control.
Alonso took the lead this time and when he came in he rejoined ahead of Hamilton, second behind Grosjean, but only just -- and Hamilton, in fine form, set him up for a thrilling passing move that he executed on the back straight on lap 21 to regain second place and, in effect the lead.
This was turned into reality when Grosjean pitted on lap 22 and the 2008 champion Hamilton began to build a lead that stretched to more than four seconds ahead of Alonso before it was reduced before he made a second stop for fresh tyres on lap 51.
Hamilton rejoined in third behind leader Alonso and Vettel, both on worn rubber, and using his fresh tyres he swiftly reduced their advantage.
It was unclear if the front two were intending to make their tyres go the distance as Hamilton cut the gap from almost 12 seconds to less than six seconds with 14 laps remaining.
By lap 62 of the 70, he was within metres of Vettel's car and searching for his opportunity to pass the German, a chance that came at the end of the lap when he moved up to second for his final chase after Alonso's Ferrari.
With six laps remaining, he was less than one second behind the Spaniard's car and waiting for an error or a chance to sweep past him - again it came on the back straight and he took it with elan, Alonso moving over and back to acknowledge he had no defence.
Vettel, struggling on worn tyres, pitted with five laps left and dropped down to fifth, thus turning the final laps into a battle of nerve and tyre-wear for those in pursuit of a podium position.