Pierre Gasly labelled victory in an extraordinary Formula 1 Italian Grand Prix as “unbelievable” after holding out Carlos Sainz by less than half a second.

The pair ran nose to tail to the line, Sainz having reeled in the race leader in the closing laps, with Gasly hanging on by just 0.4s at the flag.

Their presence at the front of the race was the result of a curious sequence of events which first saw Kevin Magnussen grind to a halt, Charles Leclerc draw the red flag, and finally a 10 second stop-go penalty for Lewis Hamilton.

For Gasly, the decision to pit on Lap 19 paid dividends as he climbed up the order as others pitted under the Magnussen Safety Car.

He then inherited the lead following a strong restart from the red flag once Hamilton took to the pits to serve his penalty.

He then hung on in the face of a late challenge from Sainz’s McLaren to cross the line victorious by just 0.4s.

“It’s unbelievable,” beamed Gasly.

“It was such a crazy race; we capitalised on the red flag.

“I’ve been through so much in the space of 18 months,” he added

“My first podium last year, I was already like wow with AlphaTauri, and now my first win in Monza. I’m struggling to realise (it).”

Gasly entered Formula 1 in 2018 with Toro Rosso (as it was then known) before joining Red Bull for 2019.

He was then bumped back to Toro Rosso in favour of Alex Albon mid-season, snagging a second place finish in the Brazilian Grand Prix.

“This team have done so much for me,” Gasly said.

“They gave me my first opportunity in F1, they gave me my first podium, now they are giving me my first win.

“It’s crazy, honestly. It’s just crazy. I’m so happy. I can’t thank them enough, everybody from AlphaTauri to Honda.

“It’s a power sensitive track and we won the race out of all the Mercedes, Ferrari and Renault cars, so just an amazing day.”

Victory also made Gasly the first Frenchman to win a Formula 1 event since Olivier Panis at Monza in 1996.

“I’ve always said coming in F1 that’s one thing we need to change, because it’s been so long,” Gasly said.

“I never expected that it would happen to us with AlphaTauri.

“We just kept focusing on ourselves since last year, working improving step by step.

“It’s crazy, honestly. I’m just so happy.”

His performance in Monza propelled the 24-year-old to eighth in the drivers’ championship with 43 points, while the team remains seventh in the constructions’ title race.

F1 remains in Italy for its next event, the Tuscany Grand Prix, which begins on Friday.