Sharks 3, Senators 2: Brent Burns snapped a tie at 7:08 of the third period and host San Jose held on to extend its season-opening winning streak to five games.
Rookie Tomas Hertl and Patrick Marleau also scored, Burns added an assist and Antti Niemi made 21 saves for the Sharks, who netted fewer than four goals for the first time this campaign.
Zack Smith and Bobby Ryan tallied while Robin Lehner stopped 47 shots in his season debut for the Senators, who are 1-1-2 on their season-opening six-game road trip.
With the contest even at 2-2, San Jose captain Joe Thornton came around from behind the net and dished the puck to Burns, who knocked it past Lehner from the doorstep to complete his second consecutive two-point performance.
After being held without a point in Thursday's victory at Vancouver, Hertl got back into the swing of things immediately. Lehner stopped defenseman Dan Boyle's shot from the right point, but the 19-year-old Hertl buried the rebound from the doorstep just 55 seconds into the contest for his league-leading seventh goal.
Hertl left the game late in the second period following a collision with Ottawa's Clarke MacArthur and did not return.
Smith drew Ottawa even with 4:39 remaining in the first period, beating Niemi from the slot after blue-liner Chris Phillips' shot from the left point went wide and caromed off the end boards. Ryan gave the Senators a 2-1 lead 3:10 later with a power-play tally.
Marleau forged a tie with a man-advantage goal with 3:48 left in the middle session. The puck squirted loose during a scrum in front of the net and made its way to Marleau, who backhanded it past Lehner from the right faceoff circle for his fourth of the season.
GAME NOTEBOOK: Senators captain Jason Spezza returned to the lineup after missing a game with a groin injury and registered an assist. ... Ryan became the first member of the Senators to score his second goal of the season. Eight other players on Ottawa have tallied once. ... Thornton's assist was the 792nd of his career, putting him within one of Guy Lafleur for 31st place on the all-time list.