Mercedes had their worst result so far this season at the Monaco GP, as Sir Lewis Hamilton lost his lead of the Drivers' Championship after finishing seventh while Valtteri Bottas was forced to retire after a pitstop debacle.
The result means that race winner Max Verstappen leap-frogged Hamilton to the top of the drivers' standings, and with Sergio Perez improving on his previous finishes to end the race in fourth, Red Bull have regained a strong foothold in the battle for the title.
And Hamilton is well-aware of the threat, telling media after the race that the team had to prevent a similarly poor result in future if they are to keep up with the competition.
"It's going to be tough," Hamilton told select members of the press, including RacingNews365.com.
"I told you at the beginning that they've got a championship winning car, and they're going to very hard to beat. I've been serious about it all year all four races, and we have won races that we shouldn't have won like in Bahrain
"But it's not over, it's a long, long way to go We definitely can't afford another weekend like this, but I'm glad I finished and got some points with fastest lap, every little point that you can get on a bad weekend like this can hopefully count for something towards the end."