Just a month ago, Sergio Perez was crowned king of the street circuits after a mighty performance in the Azerbaijan Grand Prix in Baku City. But this weekend saw another street circuit - iconic Monaco - take a big bite out of that.
“It was a really difficult day out there. Everything that could have gone wrong, went wrong,” he acknowledged. “It was the worst weekend I can remember in a while."
Although Perez was second quickest in FP3 on Saturday, his hopes of closing the gap to his Red Bull team mate in the championship standings collapsed with a costly error at the start of qualifying.
As well as a hefty repair bill and a lot of overnight work for his mechanics, it left Perez starting today's race from last place. And if there's any circuit where you don't want to be on the back row of the grid, it's surely Monaco.
The team attempted to pull off a strategic recovery by bringing Perez in at the end of the first lap to swap his medium tyres for a set of hards, gaining him a couple of positions and putting him back out in clear air.
But he soon found himself stuck behind slow traffic. And with no safety cars or red flags at all during the race, his chances of making a significant recovery into the top ten soon dwindled.
“It was going really well," he told the media in the Monaco paddock after the finish. "The conditions were tricky out there and there was some hope that when it started raining we could get things right.
"But we didn’t, it was a shame," he sighed. "Unfortunately I hit the traffic really early and that put us back in our original position."
As the frustration grew, Perez found himself involved in collisions with Lance Stroll, Kevin Magnussen and George Russell and as a result he had to pit five times during the course of the 78-lap race, leaving him mired in P16.
“I broke my front wing with Magnussen who just braked out of the chicane, and it went bad," he recalled. “I had no idea what was going on, but unfortunately I had quite some damage.
“When you are in those positions, you always have to risk a lot," he explained. “Then the rain came and I was one of the last to pit. Then I clipped the wall and it was all a mess."
It means that Perez is now 39 points behind his team mate in the drivers championship after Max Verstappen claimed another convincing win this weekend while Perez came away empty-handed.
For Perez, it all came back down to that crash in qualifying. “We paid the price for my mistake and that’s been very costly,” he said after the race.
“Really, really sad with the performance - but not off today, basically from yesterday," he said. "We knew that this was the price that we were going to pay.
“I knew that my mistake yesterday was extremely costly, and then that was 25 points," he noted. “It is very frustrating.
"I don’t think there was much we could have done differently; all the damage was done yesterday. I only want to move on from this race because it was a terrible weekend.
“I just have to apologise to my whole team because it is unacceptable to have this kind of mistake," he added. “I have to move on and learn from it. I cannot afford another zero in the championship.
"But still I have some hope," he insisted. "I really hope I can be back to my normal level in Barcelona. I need to be perfect in the next few races, I need to get victories - and get them soon."
"Unfortunately it was a difficult weekend for Checo," commented Red Bull team principal Christian Horner. "Despite his best efforts, there was very little he could do after yesterday's qualifying.
"Knowing Checo though, he will learn from his mistakes and respond quickly in Spain."