Crosby, who missed Pittsburgh's first six games with a concussion, leads the NHL with eight goals in six games. He had two goals against the Los Angeles Kings on Thursday in a 3-2 overtime loss.
"I feel good," Crosby said. "Tonight you see you get a couple of good bounces. When that's happening, you're just trying to keep shooting the puck and trust that it will go in."
Murray made his second start in three games after missing Pittsburgh's first six games with a broken right hand. He improved to 2-0-0 with his second career shutout.
Kunitz scored on a snap shot from the left circle at 4:22 of the first period. With 1:32 left in the first, Crosby made it 2-0, scoring from close range.
At the start of the second period Sharks defenseman Marc-Edouard Vlasic skated back for a loose puck in front of San Jose's crease and tried to clear it, but a hustling Crosby intercepted the pass and beat Jones with a wrist shot.
Dell gave up a goal at 2:33 to Fehr, who put a wrist shot from the right circle into the upper-right corner. Bonino made it 5-0 with a short-handed goal at 16:28 of the second.