Seattle had won their past four games but they had no answer to the Revolution at Gillette Stadium as the home side stormed to a 4-0 lead at half-time, led by a brace from Uruguayan attacking midfielder Diego Fagundez.
The result saw Real Salt Lake move within two points of Seattle in the West's standings, while the Revolution extended their unbeaten run to five matches.
With 10 minutes left in the first half, Bunbury made up for his earlier miss, finishing on the rebound, after Sounders goalkeeper Stefan Frei had saved the striker's first effort.
A counter-attack in the 41st minute saw the hosts essentially end Seattle's resistance with Bunbury producing a fine switch to Fagundez, who took one touch before volleying the ball home.
Any hope the Sounders had of pulling of a second-half comeback were dashed in the first minute after half-time when Seattle defender Chad Marshall deflected Bunbury's shot past Frei.
The victory - New England's third in a row - saw the Revolution stay in touch with the Eastern Conference-leading Sporting Kansas City on 17 points.
Morales made it 2-0 in the 17th minute from a corner but Houston pulled a goal back in similar fashion five minutes later thanks to Mark Sherrod's close-range volley.
A red card in the 27th minute changed the game when Dynamo's Servando Carrasco slid into Morales and Real took advantage after the half-hour mark through Alvaro Saborio's glancing header to make it 3-1.
A goal down, Dynamo pushed hard for an equaliser but Real managed to score next when Luke Mulholland rounded Hall with 12 minutes remaining to finish into an empty net and Morales capped off the visitors' victory and his hat-trick with an 89th minute penalty.
In Sunday's other game, Chivas USA won 3-1 at Colorado Rapids to end a three game losing streak.
