Laois were red-hot favourites to win this game but they trailed at the break by 0-5 to 1-5, after a Derek McNicholas free from 75m sailed into the net for a fortuitous Westmeath goal.
Westmeath still led by three after 50 minutes but then Laois moved up a gear and took control.
Stephen Maher fired in a goal, followed by a point from Tommy Fitzgerald and a brace from Willie Hyland, to give Laois a three-point lead. Westmeath faded after that and points from Maher and Hyland sealed the Laois win.
Scorers for Laois: S Maher 1-4 (0-3f), W Hyland 0-5, M Whelan (f), R King, C Dwyer, J Campion, T Fitzgerald, N Foyle 0-1 each.
Scorers for Westmeath: D McNicholas 1-1 (1-0f), R Greville 0-3, C Curley, N O’Brien, N Conaty, A Clarke, D Gavin 0-1 each.
LAOIS: E Reilly; D Maher, B Campion, B Stapleton; J Fitzpatrick, M Whelan, C Dunne; D Palmer, P Whelan; J Purcell, W Hyland, S Maher; N Foyle, R King, T Fitzgerald.
Subs: C Dwyer for J Purcell (25), J A Delaney for B Stapleton (inj, ht, inj), J Campion for C Dunne (44), J Fitzpatrick for D Palmer (inj, 47), B Reddin for R King (50), J Brophy for B Reddin (66).
WESTMEATH: P Collins; K Duncan, T Doyle, L Varley; G Greville, A Craig, P Gilsenan; C Curley, E Price; R Greville, A Devine, D Gavin; N Conaty, D McNicholas, N O’Brien.
Sub: A Clarke for A Craig (inj, 38).
Referee: C Browne (Galway).