Down survived a nervy closing quarter before eking out a one-point win against Westmeath in Mullingar.
Aided by a slight breeze, Down were very dominant in the first half against a lethargic home outfit.
They led by 0-04 to 0-00 with 13 minutes elapsed, three of their scores coming from lively full-forward Corey Quinn, the first of them from a free.
Against the run of play, Westmeath then fashioned a goal opportunity but James Dolan's shot was superbly blocked by Brendan McArdle.
John Heslin opened the Lake County’s account from a 15th-minute free.
Indeed, two more placed balls from Heslin were Westmeath’s only contribution to the scoreboard in the first half.
The Mourne County men continued to cut through the home rearguard with a degree of ease and they kept the scoreboard ticking over at regular intervals.
Caolan Mooney’s point in the 18th minute was an outstanding score.
Sam McCartan was denied a goal by Ceilium Doherty’s challenge on the half-hour mark, and Luke Loughlin missed the resultant 45.
Westmeath were undoubtedly flattered to be trailing by just six points at the break (0-09 to 0-03).
A Liam Kerr free increased Down’s advantage less than four minutes after play resumed.
Ronan O’Toole was black-carded a minute later to add to Westmeath’s woes.
However, a great goal from sub Fola Ayorinde in the 51st minute gave the home side a degree of hope.
Remarkably, Westmeath spurned three great goal chances during the ensuing ten minutes.
Heslin’s penalty was superbly saved by Rory Burns, and Barry O’Hagan was black-carded for his challenge on James Dolan, which led to the spot kick.
Burns then did very well to keep out Ronan Wallace’s close-range effort before another Westmeath attack saw Ray Connellan’s slapped effort somehow cleared off the line by a massed Down defence.
Three unanswered points brought Westmeath right back into contention ahead of an additional eight minutes stoppage time.
A great point from the returned O’Hagan settled Down’s nerves.
Heslin’s late free halved the deficit, but Denis Corroon shot wide from a good position with the second last kick of the contest.
Westmeath will face Cork, while Down will play Laois, in the Division 2 relegation play-offs.
Westmeath: J Daly; J Smith, K Maguire, B Sayeh; J Dolan, R Wallace, J Gonoud; S Duncan, R Connellan; D Lynch, S McCartan, G Egan (0-01, 0-01'45'); R O’Toole (0-01), J Heslin (0-06, 0-05fs), L Loughlin.
Subs: D Corroon for Lynch (33), K Martin for McCartan (h-t), B Kelly (0-01) for Loughlin (47), F Ayorinde (1-00) for Duncan (47), C Coughlan for Smith (60), T McDaniel for Martin (63).
Down: R Burns; P Fegan, B McArdle, G Collins; P Laverty (0-01), D O'Hagan, D Guinness; J Flynn, R McEvoy; L Kerr (0-01), C Doherty, C Mooney (0-01); P Devlin (0-02, 0-02fs), C Quinn (0-07, 0-04fs), C McCrickard.
Subs: T McInerney for McArdle (34), B O’Hagan (0-01) for Devlin (45), L Midleton for McEvoy (55), J Guinness for Quinn (61), K McKernan for D O’Hagan (70), S McConville for McCrickard (70).
Referee: S Lonergan (Tipperary).