Christian Horner feels Lewis Hamilton's victory at the Bahrain Grand Prix will be a tough one to take for the team but remains upbeat about Red Bull's championship hopes for 2021.
Max Verstappen was on course for victory but overtook Hamilton off the track and yielded the place to the Mercedes driver and was unable to reclaim the lead.
"It's a tough one," Horner told Sky Sports. "I think that Mercedes definitely got a very good car, they were able to push us very hard in the first stint.
"They had the undercut, they took the advantage and then the option for us was to go longer. We actually thought they [Mercedes] were going on a three stop at one point because they went so early on in the last stint.
"Max was nursing a little bit of an issue from from early on, how much of an effect that had I don't know. But it was great racing.
Horner revealed the stewards ordered Red Bull to tell Verstappen to give up the position and were not able to argue the case.
"Once you've got the instruction, you've got to you got to move out the way and he did that," added Horner. "It was fair racing, it was tough racing.
"I don't know whether Max [Verstappen] got a little bit of dirt on the tyres, he had a moment behind Lewis [Hamilton with a couple of laps to go and that seemed to just give Lewis enough of a breather, but a great race a tough one to lose.
"But you know, it's the it's the first 23 so hopefully we'll give him a harder time this year. This has been such a strong circuit for Mercedes.
"The fact that we're so competitive this weekend, I hope is a good signal for the championship. Toto [Wolff] and Mercedes have had it far too easy the last seven years, somebody needs to give a hard time.
"I think the biggest winner today is the fans. It's a tough one for us, it makes the journey a bit longer on the way home but it sets up a great season.
"I really hope we see Hamilton and Verstappen have plenty more battles."