Table: gastao_elias_match_stats
Columns: outcome
date
tournament
surface
opponent
score

Question: Who was the Opponent in the match with a Score of 6–3, 6–4?
SQL: SELECT "opponent" FROM gastao_elias_match_stats WHERE "score" = '6–3, 6–4'

Question: On what Surface was the match against Malek Jaziri played?
SQL: SELECT "surface" FROM gastao_elias_match_stats WHERE "opponent" = 'malek jaziri'