Used to express admiration or that something is as one would expect (e.g., 'as you'd expect' / 'impressive as always').
さすが先生、説明が分かりやすい。
As expected of the teacher — the explanation is easy to understand.
さすがプロだね、仕事が速い。
You're a pro — your work is fast.
試合で勝つとは、さすが強豪校だ。
Winning the match — as you'd expect from a strong team.
Used as 'さすがに ...' to indicate 'as expected, but...' often implying limits, surprise, or a reserved judgment (similar to 'after all' or 'still').
さすがに二日続けて徹夜すると疲れる。
After staying up two nights in a row, I'm understandably tired.
さすがにこの値段では買えない。
I certainly can't buy it at this price.
彼女もさすがに驚いたようだ。
She, too, seemed genuinely surprised.
Used in constructions like 'さすがの X も ...' to mean 'even X (who is usually outstanding) ...' indicating that even an exceptional person/thing is affected.
さすがの彼もこの問題は解けなかった。
Even he, impressive as he is, couldn't solve this problem.
さすがの名選手も怪我には勝てなかった。
Even a great athlete couldn't overcome the injury.