What does なかなか used by itself at the end of a sentence mean?

Question

お疲れですか?

お恥ずかしながら。昨日は日向とお弟子さんたちの前で試合だったんです。これがなかなか…

The character gets asked if he's tired. Then he replies that "I'm embarrassed but today I had a fight with Hinata in front of our students. This is..."

What does なかなか here add by itself? For what I understand the character talking later mentioned he lost to Hinata

Answer 1

これがなかなか…

Actually, it _(=試合) was rather...
However, it was quite...

• This これが is special. See the last part of my answer here: "これが喜ばずにいられると思うかい？" meaning?
• This なかなか(に) is roughly the same as むしろ ("rather") and/or けっこう ("quite/pretty/fairly"). See: Difference between なかなかに and なかなか