The Bombers overcame recent off-field adversity, an early deficit, and the Crows at their AAMI Stadium fortress, to hold the upper hand through the contest, winning 18.9 (117) to 11.16 (82).
And despite a quiet night from star recruit Brendon Goddard, it was through the midfield where the Bombers broke the Crows, with Watson (34 disposals, seven clearances), Howlett (25 touches, four goals) and Heppell (23 possessions) all crucial.
Coach James Hird this week praised his players' resilience throughout the ASADA investigation into Essendon's supplement use, and the Bombers' character was on show against the Crows.
Hird said it was a win founded on more than built-up motivation from the past six weeks.
"I think emotion only takes you so far," Hird said.
"I didn't find that the players before the game tonight were overly emotional or overly excited. Probably our first 10 minutes showed we maybe kept them emotionally a bit flatter than perhaps we could've.
"But from a point of view from the way we played the game, it obviously means a lot to us.
"[So does] every game of football we're playing at the moment because the eyes of the footballing public are on us so we want to put out a good performance."
After trailing by 20 points midway through the first term, Essendon took the lead after a six-goal second quarter.
The Crows challenged in the third term, but Alwyn Davey's three-goal effort helped the Dons to a 23-point lead at the final change.
Again the home team surged in patches throughout the last term but struggled to string together goals when it mattered. The Bombers countered their every move, and made a few of their own, with Watson and David Myers booting goals in the final minute to seal the win.
It wasn't only in the midfield where the Bombers were on top. Crows spearhead Taylor Walker kicked three goals but Jake Carlisle took the points in that battle, while half-back flanker Michael Hibberd's value continues to be undersold.
Michael Hurley, Stewart Crameri and Tom Bellchambers offered some forward targets in the first half and competed strongly, but much of the spark came from two new Bombers.
Debutant Nick Kommer was instrumental with his smarts and tenacity, while second-gamer Jackson Merrett was composed and clever across half-forward and helped set up several goals.
All summer the Crows have been asked how they could fill the hole left by former forward Kurt Tippett, and the question remains unanswered.
Walker was the main target but there were few other options, while midfielders Patrick Dangerfield and Scott Thompson had little influence.
Crows coach Brenton Sanderson said almost everything had gone wrong after quarter-time, particularly in the centre square.
"The numbers there are ugly. They just killed us in centre bounce clearances. We had our A-grade boys in there and unfortunately they got beaten tonight … so we'll have a look at that this week," Sanderson said.
It was a forgettable game for the Crows, and an equally as memorable one for the Bombers.
ADELAIDE 3.4 4.9 8.14 11.16 (82)
ESSENDON 1.3 7.5 13.7 18.9 (117)
GOALS
Adelaide: Walker 3, Douglas 2, Jenkins, Johncock, Mackay, Petrenko, Porplyzia, van Berlo
Essendon: Howlett 4, Davey 3, Bellchambers, Crameri, Dempsey, Goddard, Hibberd, Hocking, Kommer, Melksham, Myers, Stanton, Watson
BEST
Adelaide: Wright, Sloane, Douglas, Reilly, Vince
Essendon: Watson, Howlett, Heppell, Dempsey, Myers, Hibberd, Kommer, Merrett, Carlisle
INJURIES
Adelaide: Brown (left foot)
Essendon: Nil
SUBSTITUTES
Adelaide: Brodie Martin replaced Luke Brown (left foot) in the third quarter
Essendon: David Zaharakis replaced Stewart Crameri in the third quarter
Reports: Nil
Umpires: Rosebury, Meredith, Jeffery
Official crowd: 42,218 at AAMI Stadium
Callum Twomey is a reporter for AFL.com.au. Follow him on Twitter at: @AFL_CalTwomey
