Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_48890 ( "Season" text, "Duration" text, "Gagarin Cup Winner" text, "Gagarin Cup finalist" text, "Continental Cup Winner" text, "Top scorer" text )

### Question ###
Who is the gagarin cup winner when avangard omsk is the gagarin cup finalist?

### Accurate SQL ###

SELECT "Gagarin Cup Winner" FROM table_48890 WHERE "Gagarin Cup finalist" = 'avangard omsk'