Tyrone clinched the NHL Division 4 title with a passionate display in the final at the Athletic Grounds.
The Red Hands trailed by three points at half-time, but stepped it up after the break to clinch it with Rory O'Neill's 61st-minute goal.
South Down attacked strongly and led 0-9 to 0-6 at the interval, while Tyrone were restricted to breakaway raids with Liam Morgan and Paul O'Neill getting on target.
After the break Tyrone began to make inroads and were level just after the restart, when O'Neill swung over a point.
Tyrone struck the only goal of the game in the 61st minute when O'Neill drilled home an angled shot as Justin Kelly, Conor Grogan and O'Neill added points.
Man of the Match: Rory O'Neill (Tyrone)
SCORERS -- Tyrone: R O'Neill 1-4, C McErlean 0-4 (2f), C Grogan, J Kelly (1f) 0-2 each, G Fox, A Kelly, P O'Connor 0-1 each. South Down: L Morgan 0-7 (6f), P O'Neill 0-2 (1 '65'), P McAleenan, M Cunningham 0-1 each.
Tyrone -- J Devlin 6; R O'Neill 6, D Maguire 7.5, J Patton 7; S Begley 8, S Donnelly 7, M Grogan 7.5; T Hughes 6.5, A Kelly 7; G Fox 6.5, P O'Connor 6.5, C McErlean 8; R O'Neill 8.5, S McLoughney 6.5, C Grogan 7. Subs: M O'Gorman 5 for Fox, R Winters 6 for Patton, J Kelly 7 for O'Connor, B Winters 8.5 for McLoughney, C Gallagher 5 for C Grogan.
South Down -- D Kearns 6; C Teague 5.5, J McGrath 7, P Byrne 6; A McGuinness 5.5, K Courtney 8, J Brown 7; P O'Neill 7, P McAleenan 7.5; M Cunningham 6, C Beattie 5, L Morgan 8; M Magee 6, E McGuinness 7, A Brown 6.5. Subs: E Treanor 5.5 for A McGuinness, N Brown 5 for Beattie, D Doherty 5 for Cunningham, J O'Kane 5 for A Brown.
Ref -- O Elliot (Antrim).