CREATE TABLE table_10580 ("Year" FLOAT, "City" TEXT, "Rider 1" TEXT, "Rider 2" TEXT, "Horse 1" TEXT, "Horse 2" TEXT, "Association" TEXT)

Who was the second rider when papayero raced as Horse 1 in the city of rancagua?
SELECT "Rider 2" FROM table_10580 WHERE "City" = 'rancagua' AND "Horse 1" = 'papayero'
SELECT "Rider 2" FROM "table_10580" WHERE "City" = 'rancagua' AND "Horse 1" = 'papayero'