Westmeath fought back well in the closing stages of the first-half and started brightly in the second-half, but Callum McCormack, who scored four points, was their only shining light on the day.
Both sides faded in the second half but a Ken Casey goal sealed Offaly’s win.
Offaly included regular goalkeeper Alan Mulhall at full-forward while former hurling star Daniel Currams was introduced as a substitute.
Scorers for Offaly: K Casey (2-0), A Mulhall (1-2, 0-1f), W Mulhall (0-3), N Dunne (0-1)
Westmeath: C McCormack (0-4), K Martin (free), P Sheridan and T English (0-1 each)
OFFALY: K Meehan; J Gallagher, S Pender, B Darby; J Keane, P McConway, L Hiney; R Dalton, R Brady; G Guilfoyle, N Dunne, A Keenaghan; W Mulhall, A Mulhall, K Casey.
Subs: F Daly (for G Guilfoyle 28m), D Currams (for N Dunne 47m), N Smith (for J Keane 47m), B Hanamy (for A Mulhall 68m), D Kelly (for K Casey 68m).
WESTMEATH: D Quinn; M Dalton, K Sheridan, T Warburton; M Curley, M Ennis, K Maguire; T English, A Finnan; K Martin, M Gorman, P Sheridan; J Egan, C McCormack, D Mullen.
Subs: D McDermott (for T Warburton H/T), D Glennon (for D Mullen 47m), D McNicholas (for J Egan 55m),W Coyne (for M Gorman 67m), D Gavin (for P Sheridan 69m).
Referee: John Hickey (Carlow).