Sergio Perez crashed out of qualifying in Q1 after the Mexican smashed into the barrier at Sainte Devote.
Perez, the race winner from last year, will start the Monaco Grand Prix from the back of the grid after he carried too much speed into the first corner.
Minutes into Q1, Perez saw his RB19 slide into the barriers after losing the rear – causing a red flag on the session.
Upon making contact with the barrier, Perez took to the airwaves, stating: "****! I crashed. I crashed."
Fears for Red Bull will be over whether or not Perez will need a new gearbox for tomorrow's race given the hefty nature of the shunt into the barriers.
Sergio Perez will start the Monaco Grand Prix from last after his collision in Q1
The crash leaves only one Red Bull in the form of Max Verstappen to fight for pole for the rest of qualifying.
The Dutchman came close to hitting the barriers himself, but managed to save his RB19 from making any meaningful contact with the wall.
It would not phase the two-time world champion however as he would go on to top the session.