"We stopped making plays and we couldn't get out of our own zone," Coyotes captain Shane Doan said. "Their forwards were too quick and we stopped playing hockey. We have to be better than that. We let them have the extra opportunities a lot."
"The score would have been a lot worse if he didn't play like that," Phoenix coach Dave Tippett said.
Smith allowed all three goals in the first 13 minutes before blanking the Sharks the rest of the way.
"When you give up 50 shots you're going to be hard pressed to win a game on any given night," Smith said. "I kept telling myself to make as many saves as I could because I felt we were coming back."
Hertl scored his first goal 46 seconds into the game, backhanding the puck through Smith's legs after being set up in front of the net by Marc-Edouard Vlasic.
"When you put up 50 shots you get rewarded," Vlasic said. "It's good to beat that team, they're tough."
Hertl, who had an assist in the season opener, chest-bumped the glass to celebrate before he was joined by his teammates.
The Sharks made it 2-0 at 7:23 of the first period with their first power-play goal. Hertl redirected Matt Irwin's shot past Smith. Tyler Kennedy set up the score when he won the faceoff and Brent Burns kept it alive.
"He had his number," Sharks captain Joe Thornton said. "The first one was beautiful and the second one he was in the right position. Another good game for Tomas. You know he's a world-class goaltender and you have to make your shots count."
Marleau scored his second goal of the season, also on the power play, at 12:30 of the first. Joe Pavelski's shot bounced off Smith's pad and Vlasic was in position to give Marleau an open net.
Phoenix scored at 16:47 of the second period. Ekman-Larsson picked up the puck from Zbynek Michalek in his own zone and carried it all the way, taking a quick shot from the right that glanced into the net off Niemi's right glove.
Couture added an empty-net goal in the final 25 seconds.
The Sharks have beaten Phoenix in 10 of the past 12 meetings in San Jose.
The Coyotes, who play six of their first eight games on the road, head to the East Coast to play four games over the next week. ... Phoenix backup goalie Thomas Greiss, who played with the Sharks last year, received a warm reception from the crowd when he was shown on the big screen. ... The Sharks outshot Phoenix 18-8 in the first period.
Copyright by STATS LLC and The Associated Press
Arena: SAP Center Location: San Jose, California
Referees: Tom Kowal, Kyle Rehman Linesmen: Steve Miller, Pierre Racicot
Attendance: 17,562 (100.4% full)
Team Stat Comparison
Power Play Goals
Power Play Opportunities
Shots on Goal
Tomas Hertl (1)
Assist: Marc-Edouard Vlasic
Tomas Hertl (2)
(Power Play) Assists: Matt Irwin, Brent Burns
Patrick Marleau (2)
(Power Play) Assists: Marc-Edouard Vlasic, Joe Pavelski