CREATE TABLE table_17427004_7 (quarterfinals VARCHAR2, athlete VARCHAR2)

Who did Abdelhafid Benchebla face in the quarterfinals?
SELECT quarterfinals FROM table_17427004_7 WHERE athlete = "Abdelhafid Benchebla"
SELECT "quarterfinals" FROM "table_17427004_7" WHERE "Abdelhafid Benchebla" = "athlete"