Derry gained revenge for their Ulster Senior Football Championship defeat to Down with an emphatic 0-13 to 1-05 win over the Mourne men at Celtic Park.
Down only scored a single point in a second half during which Benny McArdle and Kevin McKernan were dismissed.
Star forward Ryan Bell and James Kielt had kicked the Oak Leafers into a 0-07 to 0-03 lead, but Down's Donal O'Hare grabbed an injury-time goal and his late free levelled the sides at half-time (1-04 to 0-07).
The draw had paired the Ulster rivals together for the second time in five weeks following Down's 2-17 to 1-15 win at this very venue in the Ulster Championship quarter-final.
This time, it was Derry who produced the strong second half as James McCartan's charges fell flat and only scored once, through an O'Hare free, in the entire second period.
The sides went in level at 1-04 to 0-07 at the break after Down scored 1-01 through O'Hara in first half injury-time.
But Derry recovered from the setback and kicked on, midfielder PJ McCloskey and 19-year-old forward Ryan Bell their most impressive performers.
Down could sense the game slipping away and had defender Benny McArdle dismissed on a straight red card in the 57th minute. Kevin McKernan followed suit at the very end of the game following an off-the-ball clash on Emmet McGuckin.
The game was expected to be a lot more defensive than their score-fest five weeks ago in the Ulster Championship, and so it proved.
Sweepers and wing forwards furrowing deep as wing backs was the order of the day as neither team seemed willing to open up.
Derry made a better fist of things for most of the first half and should have been ahead at the break.
They got the bodies back but did commit men forward on the counter-attack.
They had quite a strong breeze at their backs and although poor in the opening ten minutes, they made fairly good use of the wind, with the influential Bell kicking three first-half points from play.
Kielt kicked two frees, one of them a boomer from 55 metres out, as Derry stretched their lead further.
Down were relying on frees from O'Hare and did not score from play until Ambrose Rogers drove one over with the outside of the boot in the 27th minute.
A confident strike from Bell pushed Derry into a 0-07 to 0-03 lead with half-time approaching.
Brian McIver's side had led by four points at the interval in last month's Ulster tie before Down's epic second-half comeback.
This time they started the goalscoring in first half stoppage-time, O'Hare hitting the net just like he did in their first meeting.
Daniel McCartan made a rare foray forward and fed Kalum King. Despite being quickly surrounded by three defenders, he was strong enough to offload straight into the path of O'Hare whose low curling finish flew past the goalkeeper's outstretched left hand.
There was still time for O'Hare to tag on a free, drawing Down level. However, Derry played some of their best football against the breeze in the second period.
McCloskey, who missed Derry's provincial defeat to Down through injury, dominated midfield and made a number of superb high catches.
Bell starred up front hitting 0-06, including four points from play, as Down wilted. Their only score of the second half came in the 64th minute from an O'Hare free.
Disappointingly from Down's perspective, apart from the goal just before half-time, they only scored one point from play in the entire game.
Derry: E McNicholl; A McAlynn, C McKaigue, D McBride; C Kielt, M Lynch, SL McGoldrick; P Bradley, PJ McCloskey; C McAtamney, J Kielt (0-02, 0-02f), E Lynn; R Bell (0-06, 0-01f, 0-01 '45'), E Bradley (0-02), L Kennedy (0-01).
Subs used: E McGuckin (0-02) for Kennedy (42 mins), B Herron for McAtamney (53), C McFaul for Bell (70).
Down: B McVeigh; D McCartan, B McArdle, K Quinn; O Costello, P Turley, R Boyle; K King, K McKernan; A Rogers (0-01), M Poland, N Madine; C Laverty, J Johnston, D O'Hare (1-04, 0-04f).
Subs used: B Coulter for Madine (42 mins), R Mallon for Johnston (51), D Hughes for Quinn (55), D Savage for Turley (67), D Turley for McCartan (70).
Referee: Cormac Reilly (Meath)