"We know it's just one game and we have to keep working," Ottawa captain Daniel Alfredsson said. "Right now it feels great, especially to win at home and the way we played."
Ray Emery made 34 saves for his second win of the season, while Brodeur allowed six goals on 26 shots before being replaced by Scott Clemmensen midway through the second period. Clemmensen gave up two goals on 12 shots.
"It was a tough night for everybody," Brodeur said. "All the goals they worked hard for."
The last time the Devils gave up eight goals was in December 1993.
"They made us pay for every mistake we made," Devils coach Claude Julien said. "We have nobody else to blame but ourselves."
Brian Gionta scored the lone goal for the Devils.
With a total of 13 different players picking up points, the Senators finally started to resemble last season's powerhouse.
"We relaxed a little bit and started making the plays that people are used to seeing us make," Spezza said. "To get everybody in on it allows you to grip the stick a little less tightly from now on."
Spezza opened the scoring with a power-play goal, just Ottawa's second of the season with the man advantage, midway through the first period.
Gionta tied it with just over five minutes remaining in the period, taking advantage of an Ottawa turnover at its blue line. But two minutes later, Heatley restored the lead by tipping Tom Preissing's point shot.
The second period opened with a flurry of chances at both ends, with the Senators breaking the game open with five straight goals.
"Anytime you're in this business and you're trying to teach, at the end of the session you have to get some rewards as a player," Senators coach Bryan Murray said. "Tonight they got some and hopefully that reinforces what we're trying to do."
- Ottawa LW Peter Schaefer missed the game because of a hip flexor and LW Denis Hamel was a healthy scratch.
- The Devils were without D Alex Brooks (healthy scratch), C Travis Zajac (general soreness) and LW Dan LaCouture (healthy scratch).