Table schema:
CREATE TABLE table_name_55 (championship VARCHAR, outcome VARCHAR, opponents_in_final VARCHAR)

Question: What is Championship, when Outcome is "runner-up", and when Opponents In Final is "Gigi Fernández Natalia Zvereva"?
SQL: SELECT championship FROM table_name_55 WHERE outcome = "runner-up" AND opponents_in_final = "gigi fernández natalia zvereva"