In 1934, the New York Football Giants, with 5 losses, beat the previously unbeaten Bears for the NFL Championship (the Sneakers game).
Tonight, the New York Football Giants with 6 losses beat the previously unbeaten Patriots for the NFL Championship.
Unlike what you may read in some places, it was not Super Bowl 62 (LXII) but XLII. A Google search for Super Bowl LXII returned over 5000 hits and a recommendation to try XLII.