Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
against [əˈgɛnst] prep (lean) к +dat (hit, rub) о +acc (standing) у +gen (in opposition to) про́тив +gen (at odds with) вопреки́ +dat (compared to) по сравне́нию с +instr
against a blue background на си́нем фо́не
(as) against в сравне́нии с +instr
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.
Русский: