Gary Breen bagged an 82nd minute as Galway United made it two wins on the trot at Terryland Park.
Jay O’Shea’s free-kick was glanced on in a packed area by Sean Kelly, and Breen lashed Galway ahead.
For the past two seasons Galway have failed to win at home until the autumn, and new manager Ian Foster has targeted improving his team’s Terryland Park form.
And fresh from a stirring success in Inchicore when St Patrick’s Athletic were humbled Galway had ample reason to be confident.
But Sean Connor’s excellent seven match unbeaten record as a manager with Sligo Rovers and Bohemians against Galway was worthy of respect.
Having watched their players produce competent displays on the first night of the season managers Ian Foster and Connor resisted the temptation to tinker as both named the same starting XI’s.
Early on Dundalk probed for openings with Chris Turner anchoring the midfield impressively, while George O’Callaghan floated around the pitch eager to clip passes.
Galway were finding it difficult to locate time and space in the centre with Turner all bustling aggression and honest workrate.
Still for all Dundalk’s industry they didn’t threaten Barry Ryan in the first half hour as a long-range Turner free-kick on 23 minutes whistled wide.
Despite failing to match the excellence of their Pat’s performance Galway nearly claimed the lead on the stroke of half-time, but Cian McBrien’s shot was saved by Chris Bennion.
After the restart Galway enjoyed a purposeful spell and Vinny Faherty’s 54th minute header hit the crossbar.
Dundalk were reduced to 10 men in the 73rd minute when Simon Kelly was sent off for a second caution after hauling down Derek O’Brien, and then Breen landed the knock out blow.
Galway United: Ryan; Conneely, Breen, Guthrie, Daveron; O’Shea, McBrien (Edwards, 76), Kelly, McGrath, O’Brien; Faherty (Murphy, 86).
Dundalk: Bennion; Simon Kelly, Burns, Heary, Rogers; Shaun Kelly (Mulvenna, 46, McGinley, 76), Daly, Turner, Singh; O’Callaghan; O’Brien (Mansaram, 46).
Referee: M Gough (Limerick).
