A great run from second - half substitute David Williams saw Duff unleashed on the right .
The Irishman provided an inch - perfect ball across the penalty area for Koren to tap home in the six - yard box .
A great run from second - half substitute David Williams saw Duff unleashed on the right and the Irishman provided an inch - perfect ball across the penalty area for Koren to tap home in the six - yard box .