Joe Thornton also scored for the Sharks, who extended their unbeaten streak against Florida to eight games (7-0-1). San Jose hasn't lost against the Panthers since a 4-1 defeat at Florida on Feb. 9, 2000.
Olli Jokinen scored and Alexander Auld stopped 26 shots for the Panthers, who lost their second consecutive game at home after starting the season 4-0.
Vesa Toskala made 24 saves for the Sharks. It was his first game since his franchise-record 12-game winning streak was snapped in a 4-3 loss to Nashville on Thursday night.
Ehrhoff scored when his slap shot went off the stick of Florida's Ville Peltonen near the blue line and floated over the shoulder of Auld. San Jose came into the game with the best power play in the NHL but was 0-for-4 before Ehrhoff scored.
San Jose, which was limited to four shots in the second period, trailed 1-0 going into the third but tied it 1:31 in. Six seconds after the end of a Sharks power play, Thornton beat Auld with a high wrist shot through a screen.
Jokinen put Florida in front at 6:06 of the second on the Panthers' first shot of the period. He one-timed Nathan Horton's pass over the left shoulder of Toskala.
Notes: Peltonen's assist on Jokinen's goal was his first NHL point since the 2000-01 season when he played for Nashville. Peltonen spent the past five seasons playing in Finland. ... Florida C Joe Nieuwendyk missed his third consecutive game because of a back injury. ... San Jose kept intact its streak of rotating between Toskala and Evgeni Nabokov in goal every game. ... Jokinen has recorded 12 of his 13 points at home.