Sergio Perez was left reeling from the mistake which saw him crash out of Qualifying for the Monaco Grand Prix.

The Red Bull driver will start last for Sunday’s race after clouting the barrier at Sainte Devote during Qualifying 1.

Perez lost the rear of the car, which saw him impact the barrier on corner exit in an incident that drew the red flag.

“An unbelievable day. I cannot believe what I’ve done,” he said.

“It just caught me by surprise, you know, just getting the rear out of shape, especially really late into the corner, that really caught me out.

“It’s a way of how we were trying to get the lap time out of it, but just went over the limit and I became a passenger.

“There was nothing else I could do because it was really late in the corner; I could not cut the corner, or go out of the corner.

“It just came around as a big surprise,” he added.

“That is not an excuse; I should have done better today.

“All I can say is very sorry to my team because you put so much energy, so much work preparing everything, and then you just disappoint everyone.

“This is not fair for my team, so I’m super disappointed today with myself and I know that tomorrow it’s going to be an impossible race.”

Perez had traded fastest laps with team-mate Max Verstappen during Free Practice 3 and therefore headed into Qualifying as one of the favourites for pole.

That mantle went to Verstappen, who heads the championship standings.

Sitting 14 points down, that gap is likely to extend as Perez lines up last on a circuit at which overtaking is virtually impossible.

“We could have had a shot of pole, but I didn’t drive t my level so that’s why I’m here,” he confessed.

“It’s going to be a nightmare tomorrow,” last year’s Monaco winner added.

“I do expect a very difficult race. Whatever you do, people just cover you and you end up in the same position, pretty much.”