Down's result against Clare was enough for the Lake County to move up.
Westmeath sealed promotion to Division Two of the National Football League with an underwhelming defeat to Sligo yesterday.
Down's victory at home to Clare was enough to ensure the Lake County went up despite losing in Markeviecz Park on a final scoreline of 1-14 to 0-11 points.
Offaly narrowly avoided defeat, and relegation from Division Three after a one point win over Limerick in O'Connor Park.
It finished 1-10 to 0-12 points.
They'll be joined in that league next year by Laois.
Justin McNulty's side bounced back from defeat against Leitrim last time out to comfortably beat Waterford 5-19 to 0-9 points to win promotion from Division Four.
On Saturday, Laois were convincing winners over Down in the Division 2A league semi-final.
Their 1-24 to 0-13 victory means they'll be in Division 1B next year, and they play Carlow in the league final this weekend.
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