The Donegal captain and All-Star scored two of the points in the first half as the out-of-sorts hosts struggled with Down's pace and running game in the opening half hour.

But it was a different story altogether in the second period as the All-Ireland champions upped their game considerably as they outscored the Mourne men by eight points to two.

Down scored both of their second half points in the closing five minutes after Donegal had dominated and already had the grandstand in their sights.

Murphy, Ross Wherity, Colm McFadden, Rory Kavanagh, Leo McLoone, Declan Walsh and Daniel McLaughlin all got their names on the scoresheet on a night Donegal started 11 of their All-Ireland final-winning team.

The game also marked a competitive debut for 18-year-old defender Ryan McHugh, the younger brother of Mark McHugh.

Down had their noses in front at half-time as they led 0-5 to 0-4 with the Tir Chonaill posting two late points to leave just the minimum between the sides.

Donal O’Hare, with four points (three from placed balls), and Kevin McKernan were the Down scorers in the first half.

Murphy, with two frees, Wherity and McFadden each lit up the Donegal side of the scoreboard, while Down goalkeeper Michael Cunnigham denied Neil McGee with a brilliant point blank save.

However, just like they did seven days earlier against Kildare at Croke Park, Donegal improved in the second half. The only difference was on this occasion they pressed on and reeled off seven points without reply.

Murphy (0-4), Kavanagh, who boomed over a massive long range strike, McLoone and Walsh strung together those scores to push Donegal six clear by the 52nd minute.

Down pulled two points back with O’Hare picking off his second point from play in the 65th minutes and midfielder McKernan also raising a white flag, sweeping over a point on the turn. But the horse had bolted and Donegal already had the two league points in the bag.

Daniel McLaughlin, a second half replacement for Patrick McBrearty, brought the curtain down on the scoring with two minutes remaining.

Down introduced Benny Coulter in the second half but not even the former All-Star could revive the Mourne challenge.

Last year’s beaten Ulster finalists also had appeals for a penalty turned down after O’Hare seemed to be tugged as he bore down on goal. His shot at goal was turned away by Anthony Thompson for a '45'.