Dawson Mercer scored twice on the power play for the Devils (8-3-0), who have lost two straight following an eight-game winning streak. Dougie Hamilton had two assists, and Jake Allen made 23 saves.
"I don't think it was a structural issue today,” New Jersey coach Sheldon Keefe said. “I think it was a work ethic and competitive issue for us."
Eklund gave the Sharks a 1-0 lead 42 seconds into the first period. The puck bounced past Devils defenseman Jonas Siegenthaler at the point, and Eklund raced past him and beat Allen five-hole.
"It is always big when you score first,” Eklund said. “You're trying to get the momentum. That's something that you always want to do."
Kurashev extended it to 2-0 at 12:12. Wennberg found Kurashev in the slot with a pass from the left boards, and his one-timer beat Allen glove side.
Wennberg then pushed it to 3-0 at 15:47. Mario Ferraro's shot from the left boards deflected off Wennberg's leg and past Allen's blocker.
"I thought we were pretty disciplined in our own end, very detailed, and we were putting our bodies on the line,” Nedeljkovic said. “Guys were blocking a lot of shots tonight. There were a couple of times pucks came from the point where I didn't really have a good sight on it, and it ended up never getting through."