An uncharacteristic error from Lewis Hamilton and Mercedes during a safety car deployment opened the door for the young French driver, who was demoted from Red Bull to its feeder team last season due to poor performances.
The win for the Alpha Tauri car ended a run of 146 consecutive Formula One races that had been won by either Mercedes, Red Bull or Ferrari, a record stretching back to the 2013 Australian Grand Prix.
Gasly had only ever finished on the podium once before — coming second in Brazil last year — and had never previously led a lap of a grand prix. But he drove like a seasoned professional from the restart after the race had been red flagged and temporarily suspended.
It meant there was an Italian team victory at the Italian Grand Prix — just not the famous one in red that everybody would expect.
An unlikely podium was completed with McLaren’s Carlos Sainz in second and Racing Point driver Lance Stroll in third.
“Honestly, it’s unbelievable, I’m not sure I’m realizing what’s happening right now,” Gasly told Sky Sports after the race. “It was such a crazy race and we capitalized on the red flag.
“I have been through so much in the space of 18 months, my first podium last year and now the win in Monza … I am struggling for words. This team have given me so much, they gave me my first opportunity in F1, my first podium and now my first win,” he said.
“It is just amazing day,” he added. “I have said since I came into Formula 1 that we need another French winner after the last in 1996, but I never expected it to come like that.”
Gasly’s dream, Ferrari’s nightmare
Hamilton looked to be in cruise control from the start after building a commanding lead at the front of the pack in the opening few laps.
His Mercedes teammate Valtteri Bottas had hugely contrasting fortunes at the start of the race, as a sluggish start cost him dearly and he fell from second to sixth inside the opening lap. The Finn complained about a puncture over the team radio but, in truth, his driving left a lot to be desired.
McLaren, meanwhile, continued its impressive weekend and had both of its drivers, Carlos Sainz and Lando Norris, sitting in second and third in the opening stages after blistering starts off the line.
However, Ferrari’s miserable weekend — and season — showed no signs of letting up as Sebastian Vettel was forced to retire his car inside the opening 10 laps with brake failure.
The race took a dramatic twist after 20 laps as mechanical failure forced Haas driver Kevin Magnussen to pull onto the side of the track, leading the safety car to be deployed.
Race leader Hamilton and Alfa Romeo’s Antonio Giovinazzi both pitted for a tire change, unaware that the pit lane entry had been closed due to the safety car being out on the track and were both given 10-second penalties.
Ferrari’s perpetual nightmare that is the 2020 season was compounded as Charles Leclerc lost control of his car almost as soon as the safety car had ended, skidding off the track and smashing into the wall. It was a shuddering collision and there was relief throughout the paddock when the 22-year-old emerged unscathed.
Such was the extent of the damage, the tire barrier had to be repaired, forcing the race to be red flagged and temporarily suspended for the first time since the Azerbaijan Grand Prix in 2017.
When the race finally began again, Hamilton had to serve his penalty after the first lap and dropped all the way to the back of the grid, opening the door for championship chasers Bottas and Max Verstappen.
That left Alpha Tauri driver Pierre Gasly — who had never previously led a lap of a grand prix and had only once before finished on the podium — out in front and eying up his first ever race win.
In fact, only one driver in the top six had ever won a grand prix before — the 40-year-old Kimi Räikkönen.
Soon after the restart, there was a crushing blow for Verstappen as his Red Bull suffered brake failure and his chances of closing the 47-point gap with Hamilton at the top of the championship went up in smoke.
Despite plenty of pressure from Sainz in second, Gasly put in a consummate drive to hold off the Spaniard and spark wild scenes in the Alpha Tauri garage.