Cork 0-16 Down 1-8
Cork finished with 13 men but still had enough in reserve to make it three wins from three at Páirc Uí Chaoimh on Sunday.
They played with the howling wind from the start and led by 0-8 to 0-2 at the interval, showing great composure and patience against a packed Down defence.
Cork continued to force the pace on the resumption with captain Ian Maguire extending the lead within two minutes of the resumption.
And they managed to outscore their opponents during the third quarter as newcomers Cathal O'Mahony and Tadhg Corkery kicked a couple of superb points.
Cork jumped 0-14 to 0-6 in front, when they lost Seán White to a second yellow card after 55 minutes before defender Kevin Crowley went off injured.
Cork had used all their substitutes at that stage and despite a Cory Quinn goal, Down, who accumulated 13 wides, couldn't take advantage.
CORK: MA Martin; S Powter, T Clancy (0-1), K Crowley; T Corkery (0-1), L O'Donovan (0-1), M Taylor; I Maguire (capt, 0-2), B Hartnett (0-1); J O'Rourke (0-1), S White, R Deane (0-1); D Gore (0-3, two frees), C Sheehan (0-1 free), C O'Mahony (0-3, two frees).
Subs: C O'Callaghan for Sheehan (50 mins), L Connolly (0-1 free) for Deane (52), P Kerrigan for Gore (54), K O'Hanlon for O'Rourke (58), C Kiely for Powter (62).
DOWN: R Burns; G Collins, P Murdock, R McAleenan; S Annett, D O'Hagan (capt, 0-2) J Flynn; C Poland, O McCabe (0-2); K McKernan, P Devlin (0-1), D Guinness; B O'Hagan, D O'Hare (0-2, one free), J Johnston.
Subs: L Kerr for Annett and C Quinn (1-1) for McKernan (both h-t), S Dornan for Devlin (48 mins), J Guinness for Collins (51), L Middleton for Poland (65).
Referee: B Tiernan (Dublin).