Jason Spezza scored 90 seconds into the game, and the Senators jumped to a 4-0 first-period lead from which the Devils could not recover in a 5-4 victory Thursday night in Game 1 of their Eastern Conference semifinal.
Joe Corvo, Dean McAmmond, Dany Heatley and Wade Redden also scored for Ottawa, which came within a goal post of blowing the four-goal lead late in the second period.
Travis Zajac, Brian Gionta and Andy Greene scored for the Devils to cut the Ottawa lead to 4-3 early in the second period.
Scott Gomez beat Senators goaltender Ray Emery in close later in the period but, Gomez hit the post keeping Ottawa ahead.
Zach Parise did score with 30 seconds left to bring the Devils within one goal.
New Jersey played without captain Patrik Elias, who was sidelined with the effects of a lingering cold.
Coming off an impressive first-round win over Sydney Crosby and the Pittsburgh Penguins, the Senators came out flying in the first period and seemed intent on embarrassing Brodeur, scoring four times in the opening 16:39.
Brodeur struggled early in the Devils' opening-round win over Tampa Bay and the pattern was present in this game. He finished with 21 saves.
Spezza scored on a tip-in 1:30 into the game and Corvo ripped a power-play goal off Brodeur's glove at 6:49.
SHARKS 2, RED WINGS 0
In Detroit, the San Jose Sharks seized the momentum with the first goal of the series and then stunned Detroit by scoring again 24 seconds later.
Matt Carle and Mike Grier scored midway through the first period and Evgeni Nabokov made 34 saves to lead San Jose to a victory over Detroit in Game 1 of their Western Conference semifinals series.
Nabokov's shutout was his first this postseason and the fifth of his career in the playoffs. He was tied for second in the NHL with seven during the regular season.
Dominik Hasek had to make just 17 saves because the Sharks played very conservatively after taking the two-goal lead.
Game 2 is Saturday in Detroit.
Entering the series, home ice was regarded as perhaps the only advantage the top-seeded Red Wings had against the fifth-seeded Sharks.
San Jose quickly took that edge away.
Carle's goal at 9:45 of the first period was set up by a fantastic series of passes around the perimeter, ending with Joe Thornton's cross-crease pass from the corner.
The Red Wings put San Jose's powerful power play on the ice for its first goal and lost the puck in their zone to set up the second score.
Grier was in the right place when the puck trickled into the slot and he wheeled around and beat Hasek with a slap shot.
It was a much different start for Detroit after taking 2-0 leads midway through the first period in each of its first two games in the first round against Calgary.