Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
high-class [ˈhaɪˈklɑːs] adj (hotel, performance) первокла́ссный, высо́кого кла́сса (neighbourhood) прести́жный*прести́жен
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.