Trading Leather further muddled the overseas 3-year-old hierarchy with a mild upset in the Group 1, $896,511 Irish Derby on Saturday at The Curragh. The heavily favored Ruler of The World, the Epsom Derby winner, mustered no rally and finished fifth, while the well-regarded Libertarian, purchased by Godolphin after his runner-up finish at Epsom, was even less effective, coming home a meek eighth of nine.