Suffer wrong (adikoumenon). Present passive participle of adikēo. By blows (Exo 2:11).
Avenged (epoiēsen ekdikēsin). First aorist active indicative of poieō. This idiom occurs in Luk 18:7 with ekdikēsin (this from ekdikeō and that from ekdikos without right or law dikē and then exacting law of right out of ek one, exacting vengeance).
Him that was oppressed (tōi kataponoumenōi). Present passive articular participle in the dative case of kataponeo, to tire down with toil, to treat roughly, common in late Greek, in the N.T. only here and 2Pe 2:7 (sore distressed). The man was on the point of being overcome.
Smiting (pataxas). First aorist active participle of patassō, in the old Greek the beat of the heart, only in the lxx and N.T. to smite a deadly blow as here like plēssō.