As the Harvard men’s hockey team skated through warm-ups on the other side of the river to face its Jesuit city rival, hockey legend Bobby Orr was signing his book in Harvard Square.

“That’s going to be a real test for [the Crimson],” Orr said of its contest against No. 7 Boston College.

It’s fair to say that Number Four was being diplomatic. Harvard faced an uphill battle in its first home game versus the Eagles since 2009, and the road team wasted no time showing why Tuesday night in Allston.

Boston College set the tone less than five minutes into the first frame with a goal from Austin Cangelosi and did not look back, outshooting the Crimson, 17-3, in the first period before adding two more goals in each of the next frames for a 5-1 rout.

The nation’s top scorer shined brightest for the nation’s top offense. Fourteen minutes into the second, Johnny Gaudreau split the Crimson defense off a blueline-to-blueline stretch pass to beat junior goalie Steve Michalek 1-on-0 with some shifty stick work for the junior left-winger’s first of two goals on the night.

“That number 13 can make you pay in a hurry,” Harvard coach Ted Donato ’91 said of Gaudreau.

Gaudreau leads all D-I players with 1.83 points. Boston College upped its nation-leading goals per game average to 4.50 in the win.

HELLO GOODBYE

Donato and the Crimson entered Tuesday night with more options than they’ve had in more than a year. Harvard welcomed back its top defensive pair last weekend with the return of Patrick McNally and Max Everson from their year away from school, and top-line freshman center Alexander Kerfoot was back in the lineup Tuesday after going down with a shoulder injury two weeks ago.

But Harvard’s full bench would not last long. Just over 10 minutes into the first period, a sharp elbow to the head from BC captain Patrick Brown sent Everson to the ice. The sophomore defender was slow to get up, and was only able to skate off the rink with the help of his teammates.

Everson watched from the stands for the third period with a goose egg on his forehead. But he was optimistic about his condition after the contest.

“Anything with the head, [the trainers] are always very careful and will take you out just in case,” Everson said.

Everson said that he does not know whether he has a concussion, but he has never suffered one before. After sitting out the season’s first seven games, he feels more than ready to get back in a Harvard sweater.

GOALTENDING AND FRUSTRATIONS

After an all-BC first period, the Crimson controlled the flow for good portions of the game and outshot the visitors, 32-17, over the final two frames. But goaltender Brian Billett stood tall in the crease, buffering the Eagles’ lightning-strike offense with 34 saves.