Macklin Celebrini had three assists, and Mason Marchment scored in his debut for the Sharks, who were playing their season opener. Yaroslav Askarov made 23 saves.
"I thought, obviously, that first period was fast, the fastest game that I've probably seen coaching this team, and you know our guys didn't back down," San Jose coach Ryan Warsofsky said. "We can't take that many penalties (22 penalty minutes), but I like the resiliency of our group."
Eetu Luostarinen scored twice for the Panthers, who were coming off a 1-0 overtime win against the Carolina Hurricanes in their season opener on Tuesday. Matthew Tkachuk also scored, and Schmid made 28 saves in his debut with Florida.
Captain Aleksander Barkov left the game at 8:07 of the second period after going down awkwardly while battling for the puck in the right corner during a power play. After getting up, he immediately asked for the Zamboni doors to be opened and threw his gloves down on the floor while walking to the dressing room.
The 31-year-old forward was playing in just his second game for the Panthers this season after missing all of 2025-26 because of a right knee injury he sustained in the first day of that season's training camp. He had surgery the day after the injury to repair his MCL and ACL.
"He'll get looked at tomorrow," Panthers coach Paul Maurice said. "It's not related to his injury last year at all. We will have a good idea by tomorrow afternoon."
Defenseman Gustav Forsling was also a late scratch due to an upper-body injury.
Marchment put the Sharks up 1-0 at 14:20 of the first period. He got the puck along the right boards, curled above the circle and scored with a wrist shot through traffic that snuck under Schmid's pads.
Marchment signed a five-year, $33.75 million contract with San Jose on July 1.
"The fans brought the energy," Celebrini said. "We were going with all their support and how loud they were cheering. So that was great to hear."
Smith pushed the lead to 2-0 with a short-handed goal at 5:52 of the second period. Celebrini stole the puck from Tkachuk, skated in on a 2-on-1, and passed over to Smith for a wrist shot that beat Schmid over his blocker from the right circle.
"I trusted (Celebrini) to make the wall play and then he kind of took off with it, and I think they were a little bit gassed at the end of a power play, so we got a little bit of a break," Smith said.