Charles Leclerc said it was "all on me" after he "put a very strong race in the bin" in a torrid, chaotic end to his Miami Grand Prix which later saw the Ferrari driver demoted to eighth place by a stewards' penalty.
Leclerc's race had started strongly when he took the lead from the second row of the grid before dropping back to third behind Lando Norris and Kimi Antonelli after an early Safety Car period.
Still running in the final podium position into the race's closing stages, the Ferrari driver was caught and eventually passed by McLaren's Oscar Piastri on the penultimate lap and so dropped to fourth.
But Leclerc's race then went badly awry on the final lap.
He spun into the wall at Turn Three, damaging his car, and although he was able to continue on, he struggled with the SF-26 over the remainder of the lap and dropped behind Mercedes' George Russell and Red Bull's Max Verstappen to sixth place over the final two corners.
Race stewards then placed Leclerc under investigation for corner cutting after his spin, driving which would eventually earn him a 20-second penalty in lieu of a drive-through - a sanction which dropped him two further places to eighth behind team-mate Lewis Hamilton and Alpine's Franco Colapinto in the final classification.
Speaking before the penalty was applied, a frustrated Leclerc told Your Site F1 on how his final lap unravelled: "It's all on me and I don't have much to add other than that.
"Very disappointed with my mistake.
"It shouldn't happen. I pushed very hard on the second to last lap, I thought it was a good idea to kind of let Oscar go for me to get the overtake.
"I knew it was going to be very difficult to stay in front otherwise. But it was a very poor decision, and in the space of four corners I put a very strong race in the bin, so I'm very frustrated about that."
On his driving as he tried to get his ailing car to the finish, Leclerc said: "The thing I can say is that I did my best to try to make the corners, first of all. It was probably a lot more difficult than what it looked from outside."
Leclerc told stewards that the car would not take right-hand turns properly after contact with the wall but officials ruled after their investigation that "the fact that he had a mechanical issue of some sort did not amount to a justifiable reason" for cutting several corners.
"We determined that the fact that he had to cut the chicanes (i.e. to leave the track) meant that he gained a lasting advantage by leaving the track in that manner," stewards said.
"We accordingly impose a Drive Through penalty on Car 16 [Leclerc], given the number of times the car left the track and gained an advantage."
The Ferrari drivers had crossed the line in sixth and seventh places, with Hamilton nine seconds behind Leclerc after a race in which he had carried car damage from the first lap following contact with Colapinto.
Having already finished seventh in Saturday's Sprint, Hamilton admitted it had proved "not a good weekend at all", although felt he had been unfortunate on Sunday.
"Seventh and a seventh, just in no man's land in both races, but particularly today with the damage," he said.
"There was nothing I could do. Really unfortunate because the team worked so hard. To come away with xx points - we have to move on from here."
"I was unlucky with Max spinning [at the second corner], I had to go to the right of him.
"I had a good Turn One and I was in a good position and then the only way I could go was right. Then I lost positions from there, and then I think it was Franco that hit me, and I lost a lot of performance from there."
Formula 1 next heads to Montreal for the Canadian Grand Prix and another Sprint weekend. Watch live on Your Site F1 on May 22-24.
