The Buffalo Sabres thought the officials got it all wrong.
Marchand scored the first overtime penalty shot in franchise history, and the Bruins beat the Sabres 2-1 on Saturday night.
Marchand got the penalty shot after being grabbed by defenseman Rasmus Ristolainen 2:32 into overtime. The Bruins wing came in on goalie Robin Lehner, shifted to his backhand and slipped a shot inside the right post for his ninth goal in nine games.
The Senators thought Marchand did not have clear separation from Ristolainen, and Lehner was upset after the game ended and threw his mask at the bench.
"That's just embarrassing," he said. "I hope (the referee's) embarrassed. I am embarrassed. It shouldn't end like that. Disappointing thing is that I might get fined or whatever, but it's just embarrassing."
Sabres coach Dan Bylsma was less animated but agreed.
"Rasmus is right there with him, and the judgment of the referee awards a penalty shot, and I'm not sure I see it the same way," he said.
Boston defenseman Joe Morrow even seemed surprised by the call.
"I wish I could tell you what dictates a penalty shot and what doesn't," he said.
Marchand has scored in eight of his last nine games and leads the team with 24 goals
"When you're feeling good and confident, you seem to bear down in situations like that," Marchand said.
"He could have done whatever, go down and slide on his stomach, and it's going to go in," Boston defenseman Torey Krug said. "When you're hot, you're hot. I'm glad he's on our side right now."
Loui Eriksson also scored while the Bruins improved to 7-2-1 in their last 10 games. The Bruins beat Buffalo 3-2 in a shootout in the first of a home-and-home on Thursday night.
Sam Reinhart scored for Buffalo. The Sabres have points in a club-record eight straight road games (6-0-2).
Tuukka Rask made 37 saves for Boston, and Lehner had 36.
It was the second professional game in Boston for Buffalo's rookie star Jack Eichel. He won the Hobey Baker award as college hockey's best player in his only season at Boston University before turning pro last year.
Last time, the 19-year-old had two goals and two assists in a 6-3 win on Dec. 26. He was minus-1 with two shots on goal in this one.
Eichel, who grew up about 35 miles north of Boston in Chelmsford, led the Terriers to the NCAA championship game, which they lost to Providence in TD Garden last April.
The Bruins jumped ahead on Eriksson's goal 12:22 into the opening period. David Krejci collected the puck deep in Buffalo's zone and sent a cross-ice pass to David Pastrnak, who fed Eriksson across at the edge of the crease. The wing fired it into the net before Lehner could get back across.
The Sabres tied it on Reinhart's goal 10:53 into the second. Marchand turned the puck over and Reinhart scored off the rebound of Jamie McGinn's shot by slipping a backhander behind Rask from below the right circle.
Both teams had good scoring chances in the second, but Lehner had the tougher stops. He made a left-pad save on Pastrnak and came across to get his stick on the wing's wraparound bid seconds later.
Lehner also flashed his right pad to stop Eriksson's wrister from the slot with about 4 minutes left.
NOTES: Buffalo LW Marcus Foligno was out with a lower-body injury. ... Eriksson needs two goals for 200 in his career. ... Eichel, selected second overall in the 2015 draft, came in with 21 points (seven goals, 14 assists) in his last 20 games. ... Thirty years ago, Buffalo's Dave Andreychuk scored a club-record five goals in a game against Boston at the old Boston Garden. He was just the ninth player in NHL history to score five on the road. ... Boston's Zdeno Chara appeared to inadvertently bump a referee during scrum behind the net late in the second.