The loss was the third in four games for the Bruins, and they finished the three-game California tour with a lackluster 1-2 mark and six goals — five by Geekie. Including last Monday’s 3-1 loss to the Hurricanes, the Bruins have scored only seven over their last four outings.

“We [have to] just relax here,” said coach Marco Sturm, asked postgame if there was a way for his club to boost its scoring volume. “Our power play [0 for 3 Sunday], we [have to] be a little bit sharper, and five-on-five. And traffic, we [have to] be a little bit better – we have the size for it, and the toughness for it — but for some reason we are not being in front of [the goalie]. That’s an area we have to correct.”

Get Starting Point

A guide through the most important stories of the morning, delivered Monday through Friday.

Another bugaboo has been the Bruins’ propensity to take penalties. The Sharks were on the advantage six times (including 1:49 of five-on-three). The Bruins, particularly during their early-season six-game losing streak, too often have seen their offensive game get lost in the parade of Black and Gold sweaters to the penalty box.

“It’s every game,” said a frustrated David Pastrnak, who set up the Geekie goal midway through the third. “We’re taking almost double the penalties that we have power plays, so it’s tough . . . too much relying on the penalty kill.”

Also, noted Pastrnak, the constant stress on the PK takes the “tempo” out of the offense.

“We just [have to] stay out of the box, and be better,” he said. “[Goalie Jeremy Swayman has] been standing on his head. It’s tough.”

Swayman, following his 31-save performance two nights earlier in a 2-1 overtime win in LA, turned in 28 more, but the pair of goals allowed by midway through the second period proved too much to overcome.

Collin Graf added an empty-net strike to close out San Jose’s scoring.

Geekie cut the deficit to 2-1 when he knocked home a feed from Pastrnak with 10:02 gone in the third.

The 13-11-0 Bruins wrap up their four-game road trip Wednesday in Elmont, N.Y., against the Islanders.

“California is always one of the toughest trips,” said Pastrnak. “Always low-scoring games. You have to bear down on your chances when you can, but at the same time, it’s hard to find the tempo of the game. You could see in the third, we started to get in the tempo a little bit better. It’s just my opinion, but we don’t get enough to the net, and that’s where you [draw] the penalties.”

Jeremy Swayman made 28 saves, seven on Will Smith alone, but took the loss against the Sharks while making a second consecutive start.Jeff Chiu/Associated Press

The second of the San Jose strikes was provided by Celebrini on a power play at 11:45 of the second period.

Only 26 seconds after Jonathan Aspirot was whistled off for a tripping minor, the dazzling Celebrini fired a wrister by Swayman from the left faceoff circle. Celebrini is very light and nimble, an artful skater able to dart in and out and create good shooting positions.

Aspirot’s penalty came only seconds after Dmitry Orlov delivered a low, menacing hit on Sean Kuraly, one in which the former Bruins defenseman low-bridged him. (It certainly would have sent Brad Marchand to the penalty box in his Boston days.)

“What do you call it when someone has their legs taken out from under them, you tell me,” said an even-tempered Kuraly, relaying what he asked the officials. “I didn’t like it. Both my knees were hyperextended . . . but, hey, what are you going to do?”

The Sharks, with renewed hope after some very lean years, moved out to the lead with 4:07 left in the first period, soon after failing to convert on a power play.

Mukhamadullin connected for the go-ahead goal, snapping home a wrister from the right wing circle that appeared to tick off Mikey Eyssimont’s stick before ramping up over Swayman’s shoulder.

It was the third time in the last four games the Bruins surrendered the opening goal and the 12th time in 24 overall. The Bruins are 8-4-0 when connecting for the 1-0 lead, with Geekie’s name on three of those 12 goals, and 5-7-0 when the opposition scores first.

The Bruins welcomed No. 1 center Elias Lindholm back after a 10-game absence (knee).

“Good to be back,” said Lindholm. “You just try to get the rhythm going and do what you can. Happy to get one out of the way for sure.”

Lindholm logged 15:41, including 4:12 on the power play and 1:02 on the penalty kill. He said he felt 100 percent healed.

“When an injury like that happens, obviously you want to come back right away,” he added. “I think am still ahead of the timeline — good to be back, for sure.”

Kevin Paul Dupont can be reached at kevin.dupont@globe.com.