CREATE TABLE table_41960 ("Date" TEXT, "Tournament" TEXT, "Winning score" TEXT, "Margin of victory" TEXT, "Runner ( s ) -up" TEXT)

What is the name of the tournament played on Sep 20, 1981, ending with a margin of vicroty of 2 strokes?
SELECT "Tournament" FROM table_41960 WHERE "Margin of victory" = '2 strokes' AND "Date" = 'sep 20, 1981'
SELECT "Tournament" FROM "table_41960" WHERE "Date" = 'sep 20, 1981' AND "Margin of victory" = '2 strokes'