@CK, you left a tag saying that the Japanese and English don't match. What does the Japanese say?

舞台 = stage / the act done on the stage
Literal translation is "It/That was the best stage."
Perhaps, "The performance was excellent."?
@CK
What do you think?

CK doesn't have e-mail notifications enabled, so he might not have seen our questions.

@small_snow @Pfirsichbaeumchen

I imagine the scene when audiences who have seen orchestras and plays are moved by the most wonderful performances they have ever seen, standing up in total awe, applauding and saying.
In this case, I think perhaps 最高の舞台だった means the followings:
- What an excellent show(theater/movie)!
- Your/the performance was excellent.
- Your/the play was truly amazing!
or
- You did such a fantastic performance.
- I have never seen such a best performance ever.
- They had an amazing performance (athlete/actor)

Also, I often come across (the Japanese Olympic) athletes who have been able to play/perform satisfactorily on the highest stage, the Olympics, say this in interviews.
In this case, perhaps 最高の舞台だった means the followings:
- I/We had the best stage.
- I was(/We were) satisfied with my(/our) performance (at the Olympics, which is on the highest stage).

I don't know how to say it naturally in English as usual. And, to be honest, I don't even know if other countriess' athletes would say that. Sorry for the long explanation. I hope this helps you.

If anyone would like to see that video, even though it is in Japanese;
https://www.gorin.jp/video/6267013487001 (about 0:25 - 0:35)

As always, I'm more interested in fixing a mistaken sentence or translation than in simply learning that the sentence is problematic, or being told additional ways not to translate it. Based on KK_kaku_ and small_snow's comments (thanks!) I've changed this to "The performance was excellent."