Roscommon suffered defeat in their Allianz National Football League Division One South opener against Dublin.

The boys in blue ran out 1-22 to 0-16 winners in Dr Hyde Park.

The Rossies put up a commendable challenge and trailed the six-in-a-row All-Ireland champions by 1-12 to 0-9 at the break.

Cormac Costello with the goal for Dessie Farrell's men in the first-half.

Roscommon manager Anthony Cunningham was bemused by the new penalty rule.