Chelsea were held to a 2-2 draw in the Europa League semi-final tie between the two clubs, but the Blues progressed to the final after winning a penalty shootout.
Da Costa feels that Eintracht Frankfurt went toe-to-toe with Chelsea for the full 120 minutes at Stamford Bridge in the second leg.
Eintracht Frankfurt put out Inter and Benfica on their run to the semi-final, but Da Costa insists that Chelsea were on a different level to the two sides.
And he thinks that in matching Chelsea, the entire Eintracht Frankfurt team grew in confidence.
“We had played against top teams like Inter or Benfica before, but Chelsea was another level. Already in the first leg they appeared with a matter of course – unbelievable”, Da Costa told German daily Bild.
“But we were on an equal footing, able to keep up with the level because everyone has outgrown themselves.
“That’s why these two semi-final games are something very special for me, whereby I would like to rate the game at Stamford Bridge a bit higher because we delivered a fight for them over 120 minutes.”
Eintracht Frankfurt finished in ninth place in the Bundesliga this season, picking up 45 points from their 34 games.
