Drogheda were quickest out of the blocks and immediately forced two corners, one of which led to a Michael Daly shot which was blocked by a defender in the crowded six-yard area.
But Dundalk countered with purpose and Kurtis Byrne was denied by a fine save from Micheal Schlingermann after Brian Gartland deflected a corner kick into his path.
That was just a taste of what was to come as two goals arrived in the space of 30 seconds approaching the 20-minute mark, one at each end.
The Lilywhites struck first when Darren Meenan’s measured corner was powerfully headed home at the near post by Patrick Hoban, but the celebrations in the packed away end were still going on when Drogheda’s Carl Walshe nodded the ball down towards Gary O’Neill who turned in the box before rifling high past Peter Cherrie.
There were good opportunities at both ends after that, with Ciaran McGuigan heading a corner wide for the Drogs and Daryl Horgan stretching to divert a Sean Gannon cross just wide.
But coming up to half-time Dundalk looked the more likely to make the second breakthrough. Schlingermann had to race back to his goal quickly to stop a Horgan effort after being forced out of his goal by a short backpass, and Dundalk right-back Sean Gannon then fired into the side netting from a promising position.
When play restarted it was Drogheda in the ascendancy, however, and Cathal Brady warmed the hands of Cherrie with a stinging hook shot.
Dundalk responded with free-kicks from Richie Towell and Kurtis Byrne, neither of which troubled Schlingermann as the game remained finely balanced.
At the other end, Brennan was then unlucky to see his 73rd Shields on the back of the head, and Drogheda then had an escape as a snap shot from Meenan was saved by the legs of Schlingermann.
With news of Cork having beaten St Pats in the earlier kicker-off, Dundalk were more in need of a winning goal than their
hosts, but they couldn’t fashion another chance and the game ended in deadlock.
DROGHEDA UNITED: Schlingermann; Doyle, McNally, McGuigan, Grimes; C Brady, Daly, Holohan, Brennan, Walshe; O’Neill.
Subs: McGlynn for Daly (79min), O’Brien for O’Neill (90 +2min).
DUNDALK: Cherrie; Gannon, Boyle, Gartland, Massey; Meenan, Towell, Shields, Horgan; Byrne; Hoban.
Subs: McDermott for Byrne (71min), McMillan for Hoban (84min), Mountney for Horgan (90 +2min).
Referee: Neil Doyle (Dublin).