The Sharks fell from the ranks of the unbeaten Sunday after they failed to start on time in a matinee at TD Garden in Boston.
Playing their fourth game in six days on a season-opening road trip, the Sharks allowed first-period goals to Brad Marchand, Derek Forbort, and David Pastrnak and never fully recovered in a 4-3 loss to the Boston Bruins.
Down 4-1 in the third period, Tomas Hertl and Timo Meier both scored in a span of 1:49 to draw the Sharks within one goal with 4:52 left in regulation time. But the Sharks couldn't get the equalizer as they suffered their first loss in five games this season.
Pastrnak's goal at the 16:12 mark of the first period gave the Bruins a 3-0 lead and marked the first time this season that the Sharks had allowed a power-play goal after killing the first 10 man advantage tries.
San Jose (4-1-0) got that one back just 32 seconds later as rookie center Jasper Weatherby beat Bruins goalie Linus Ullmark from a sharp angle for his second goal of the season. But Boston went back up by three less than six minutes into the second period as Jake DeBrusk beat Adin Hill with a shot from in close after he had gotten past defenseman Radim Simek.
That was it for Hill, who was pulled by coach Bob Boughner after he allowed four goals on 14 shots. Hill came into Sunday with a 3-0-0 record and a .922 save percentage.
James Reimer made eight saves for the remainder of the period and finished the game.
Reimer finished with 20 saves. Ullmark had 22 for the Bruins, including seven in the third period.
The Sharks 4-0-0 record marked the best start to a season since 2015, and another win would have marked their first season-opening five-game win streak since 2013.
The Sharks finish their five-game road trip Tuesday in Nashville against the Predators, then head home for a five-game homestand that starts Thursday against the Montreal Canadiens.
LINEUP CHANGES: Boughner made two changes to his forward group, inserting Alexander Barabanov and Jonah Gadjovich and scratching Lane Pederson and rookie William Eklund.
Eklund, 19, had three assists in his first three NHL games but played just over 11 minutes and did not have a point in the Sharks' 5-3 win over the Toronto Maple Leafs on Friday. Eklund was the Sharks' leading scorer with six points in five preseason games, helping him crack the roster for the start of the regular season.
"He's, I don't want to say hit a wall, but he played four games in seven nights, and he played almost every preseason game. He's played a lot of hockey," Boughner said, "so it's just time to let him watch a game. I think I'd be good for him, actually, to watch from (the press box)."
Eklund can play up to nine NHL games before the Sharks must decide whether to keep him with the team and burn the first year of his entry-level contract or return him to Djurgardens in Sweden, in which case he would still have three years left on his deal.
Gadjovich, one of the Sharks' bigger forwards at 6-foot-2 and 210 pounds, picked up his first career NHL point on Weatherby's goal. Gadjovich, who was put on waivers by the Vancouver Canucks on Oct. 6 and officially claimed by the Sharks the next day, had played one NHL game before Sunday. That came in May with the Canucks.(c)2021 the San Jose Mercury News (San Jose, Calif.) Distributed by Tribune Content Agency, LLC.