While the captain sat in the box, the Anaheim Ducks scored on the power play to trim Detroit's lead to one goal.
Zetterberg worried he had unleashed another crazy finish in this wild series.
Instead, the Red Wings coolly wrapped things up on the coast and calmly moved on to an even bigger challenge much closer to home.
Zetterberg and Valtteri Filppula each had a goal and an assist, and the Red Wings finished off Anaheim with a 3-2 victory Sunday night.
Justin Abdelkader scored a short-handed goal and Jimmy Howard made 31 saves as the seventh-seeded Red Wings won three of the first-round series' final four games to oust the Ducks, who had the NHL's third-best record in the regular season.
"We did a great job getting off to a good start, and then we protected it there at the end," said Zetterberg, who scored three goals in the series' final two games after getting blanked in the first five. "A lot of us have been in tough situations like this before, so we knew how to play this type of game."
Detroit faces top-seeded Chicago in the second round, and the Red Wings already are relishing the prospect of shorter flights during their final postseason in the Western Conference.
After the clubs played four overtimes in the series' first six games, the Red Wings largely dominated the anti-climactic clincher -- and for the first time in the series, the Wings didn't even need overtime to win.
"It just says there's no quit in this dressing room," Howard said. "The belief in here is we can play with anybody."
His penalty notwithstanding, Detroit got a big finish from Zetterberg, their Stanley Cup-winning captain, who scored just 1:49 into Game 7 on a rebound in the slot. Zetterberg finished with seven points in the series' final three games after just one assist in the first four.
"It was not the best move by me, so it was tough to sit in the box," Zetterberg said. "But we still had a one-goal lead, and we've been in these situations so many times before."
After winning a Game 7 on the road for just the third time in their franchise's lengthy history, the Red Wings are in the second round for the sixth time in seven seasons.
Detroit didn't clinch its 22nd straight playoff spot until its final regular-season game, but the Wings beat Anaheim in a seventh game for the second time in five seasons.
The Motor City's team even prevented the first Freeway Faceoff in NHL playoff history. Anaheim would have faced Los Angeles in the second round, the first postseason matchup for Southern California's two teams.
Emerson Etem also scored and Jonas Hiller stopped 29 shots for the Ducks, who couldn't capitalize on home ice and failed in their second chance to close out their first playoff series since 2009. Another slow start doomed Anaheim, which fell behind 2-1 late in the first period on Abdelkader's goal.
"We felt we had a good thing going," Hiller said. "I think everybody thought we were going to go a long way, but it seemed like we didn't find that extra step for the playoffs. Detroit was just a little better than us. It's depressing. It makes you feel sad."
The loss completed an ugly flop for Anaheim, which had the best winning percentage in franchise history while winning just its second Pacific Division title during the lockout-shortened season.
The Ducks' defeat also is a sadly familiar playoff disappointment for coach Bruce Boudreau, who never got the Washington Capitals past the second round after four standout regular seasons with his previous club.
The loss also could be the final NHL game for Teemu Selanne, the 42-year-old franchise scoring leader who flirts with retirement every summer. The Finnish Flash said he'll take his customary several weeks before deciding his future.
"It's very disappointing," Selanne said. "We had two chances to close the series, but couldn't. ... As a group, we have to learn something from this. The playoffs are so much fun. We were looking forward to going forward and enjoying this a whole lot more."
Selanne didn't score a goal in the series' final six games -- but Corey Perry, the Ducks' former 50-goal scorer and NHL MVP, didn't score a goal in the entire series despite 24 shots.
"It's not something you think is going to happen," Perry said. "You get the job done throughout the year, but it just didn't seem to be there in this series."
The clubs alternated victories until the final two games of the series, with the Ducks taking three straight one-game leads before Detroit caught them.
The Wings earned a third trip to California with an overtime win in Game 6 on Friday night -- and they made it count with the Wings' fourth win in six appearances at Honda Center this season.
Anaheim had another packed house on hand for just the second Game 7 in Honda Center's history, but the Red Wings dominated from the start.
Detroit created choking traffic in front of Hiller immediately, and a rebound of Filppula's long shot went straight into the slot for Zetterberg.
The Ducks appeared overmatched early, but Etem -- the 20-year-old Long Beach native -- had all the poise his teammates lacked. Etem attempted to dump the puck into the Detroit zone, but instead collected a deflection and skated in on net, firing a shot over a prone defenseman and past Howard for the third goal of his first NHL playoff series.
Detroit went right back ahead when Abdelkader stole Beauchemin's pass near the blue line during the power play. Abdelkader easily skated away from Sheldon Souray and beat Hiller on a breakaway for his first goal since returning from a two-game suspension.
The Red Wings again took control in the second period, and Filppula put them up 3-1 when he jumped on a loose puck and fired a backhand through Beauchemin's legs for his first goal of the postseason.
Anaheim D Toni Lydman missed his fourth straight game since getting hit in the head by Abdelkader, who served a two-game suspension and returned for Game 6. ... The Red Wings scratched C Cory Emmerton for the first time in the series and activated RW Patrick Eaves, who sat out Game 6. D Carlo Colaiacovo stayed in the lineup for the second straight game. ... Anaheim's only previous Game 7 at Honda Center was in 1997, when the Ducks beat Phoenix for the franchise's first playoff series victory. Selanne was in his first full season with the club.