CREATE TABLE table_203_793 (id DECIMAL, "#" DECIMAL, "date" TEXT, "venue" TEXT, "opponent" TEXT, "score" TEXT, "result" TEXT, "competition" TEXT)

who was the opponent before mexico ?
SELECT "opponent" FROM table_203_793 WHERE "date" < (SELECT "date" FROM table_203_793 WHERE "opponent" = 'mexico') ORDER BY "date" DESC LIMIT 1
SELECT "opponent" FROM "table_203_793" WHERE "date" < (SELECT "date" FROM "table_203_793" WHERE "opponent" = 'mexico') ORDER BY "date" DESC NULLS LAST LIMIT 1