Holders Dublin lived on their wits in Mullingar before applying a late burst of scoring to win 0-14 to 1-07 and keep their 100% Allianz League Division 1 record intact.
Westmeath sub Des Dolan threatened to make the Dubs pay for a string of misses with a brilliant 50th minute goal to level the game.
But a run of seven Dublin points in the final 15 minutes eased them to victory.
Jim Gavin's side were superbly led in the closing minutes by sub Paul Hudson who kicked four points - three from open play.
Ciaran Kilkenny also impressed at centre-forward while Westmeath 'keeper Darren Quinn pulled off a number of stunning saves.
The result keeps the All-Ireland champions in pole position in the league ahead of the three-week break before they play Cork on 1 March.
Hosts Westmeath were seeking just their second league win over Dublin since 1969.
They came into the contest with the memory of last month's 0-12 to 0-11 O'Byrne Cup defeat at the same venue still fresh.
Kilkenny scored the winner in that encounter and got Dublin off the mark this time with a third minute free. Kevin McManamon doubled Dublin's advantage shortly after but the visitors never quite took off as anticipated.
The sides were back level at 0-2 and 0-3 apiece inside the opening 15 minutes. John Heslin, a late addition to the Westmeath full-forward line following fears of an ankle injury, scored two points.
But back-to-back Dublin points from Ciaran Reddin opened up clear daylight between them again.
Despite playing into the wind, Dublin were dominant and should have extended their lead by further. As it was, they took a 0-6 to 0-3 lead into the half-time break with Stephen Cluxton pointing from a 45. Paul Mannion missed two good chances from frees while Kilkenny dragged another wide and McManamon hit the post.
Westmeath ended a 23-minute barren streak with an inspirational Ray Connellan point after the restart, leaving two in it again.
But while Cluxton converted another 45 they would rue missed goal chances by Michael Darragh Macauley and Paul Flynn.
Westmeath sub Dolan was much more clinical with a goal chance just moments after his arrival.
He accepted Ger Egan's pass on the right of goals and drilled a brilliant shot across the 'keeper to the net. It tied the scores at 1-4 to 0-7 and they were level again with 15 minutes to go.
But four Dublin points without reply ultimately won them the game and they added three more in the dying minutes.
Sub Paul Hudson hit four in total while Kilkenny and Cluxton converted placed balls to give them breathing space.
Dublin: S Cluxton (0-03, 0-03 45), P McMahon, M Fitzsimons, D Nelson, E Lowndes, C O'Sullivan, J Cooper, MD Macauley, S Carthy, P Flynn, C Kilkenny (0-03, 0-03f), C Reddin (0-02), P Mannion, E O'Gara, K McManamon (0-01).
Subs: J McCaffrey for Macauley (blood), P Hudson (0-04, 0-01f) for McManamon 51, K O'Brien for Nelson 51, D Byrne (0-01) for O'Gara 58, McCaffrey for Macauley 60, K Nolan for Cooper 67.
Westmeath: D Quinn, K Maguire, K Gavin, S Gilmore, J Gonoud, J Gilligan, J Dolan, D Duffy, D Corroon, P Sharry, J Egan, G Egan, K Martin (0-01), Denis Glennon, J Heslin (0-05, 0-03f).
Subs: R Connellan for Maguire (blood), Connellan (0-01) for Corroon, Des Dolan (1-00) for Martin, Damian Dolan for Gilmore, D McCormack for Glennon.
Referee: D Gough (Meath).