4 takeaways as James Hagens stays hot in Bruins' win over Vegas

After three straight subpar efforts, the Boston Bruins knew they were going to need to step it up Monday night with the defending Western Conference champion Vegas Golden Knights in town.

For most of the night, they did. This was a much better all-around effort from the Bruins, and even though they did let a two-goal lead slip away, they battled through for a big 3-2 shootout win, with David Pastrnak scoring the lone goal in the shootout.

Here are four takeaways from the win:

Hagens, linemates keep rolling

The Bruins' "third" line of James Hagens, Elias Lindholm and Casey Mittelstadt has quickly become their best line. They kept it rolling Monday night with Hagens finishing off a feed from Lindholm for the game's opening goal.

It came just 7:23 in, and it was at the end of a second straight dominant shift in the offensive zone for that trio. Defensemen Nikita Zadorov and Will Borgen both nearly scored earlier in the shift off setups from the forwards, before Hagens finally finished the job.

Hagens, who turns 20 on Tuesday, now leads all NHL rookies in goals (6) and points (12). He is also tied for ninth among all NHLers in 5-on-5 goals (6) and tied for 12th in 5-on-5 points (11).

"I did not," Hagens said when asked if he was aware he leads all rookies in goals and points. "Honestly, it’s been really fun just being here, being a part of this. That stuff doesn’t matter when we win. You heard the building tonight. It was one of the best feelings in the world."

In 113 minutes together at 5-on-5, the Mittelstadt-Lindholm-Hagens line has now outscored opponents 7-2 and they have an expected goals share of 58.5%. Bruins coach Marco Sturm continues to match them up with opponents' top lines, too, which on Monday was the trio of Jack Eichel, Mark Stone and Ivan Barbashev. During the 10-plus minutes that they went head-to-head, the Bruins led 15-9 in shot attempts, 3-0 in high-danger chances, and 1-0 in goals.

"Sure," Sturm said when asked if Hagens is exceeding expectations. "If you look at his points and goals, definitely I would say yes. He's been great. He's been on a great line. He's trying to do the right thing. He's scoring. He's having some points. He's having some fun. So he's definitely on the right track."

Geekie heating up

The Bruins' second goal of the night came on the power play off the stick of Morgan Geekie, who found space in the slot and buried a feed from Pavel Zacha. After scoring just one goal in the first 14 games this season, Geekie has now scored in two straight.

Goals do tend to come in bunches for Geekie once he gets going, so the Bruins are certainly hoping that's what's happening here. Monday's goal coming on the power play was also nice, as it snapped an 0-for-10 skid for Boston's man advantage. Geekie's game-tying goal on Saturday also came in a man-up situation, a 6-on-5 with the extra attacker on in the final minute of the game.

"It's obviously nice to see them go in, but I think for me, maybe it's just a product of being in the right place at the right time," Geekie said. "We've kind of spun it around on the power play the last few games, so I think for us to be able to capitalize on that one was huge. It always feels good to see one go in."

Poitras leaves, returns, leaves again

Geekie's goal actually came during a five-minute power play, which the Bruins got as a result of Braeden Bowman elbowing Matt Poitras directly in the face. Bowman got a game misconduct as well.

Poitras was leaking quite a bit of blood as he left the ice. He briefly returned to the bench with a full bubble over his face, and some gauze shoved up his nose, but didn't take a shift and eventually went back to the locker room for good.

Sturm didn't have an update on Poitras after the game. I'm no doctor, but a broken nose seems like a pretty good bet on this one. We'll see in the next couple days if Poitras is able to practice ahead of a Thursday trip to Pittsburgh.

More undisciplined play from a leader

One of the biggest negatives for the Bruins in this one was that Charlie McAvoy took three penalties. Vegas scored on the ensuing power play after the second one to cut Boston's lead to 2-1. But it was what happened right after that that could have been disastrous.

McAvoy clearly wasn't happy about either of his first two penalties, and let the refs know it on his way to the box on both occasions. When Vegas scored, McAvoy got in one of the ref's ears again as he left the box. The ref decided enough was enough and sent McAvoy right back to the box for an "abuse of officials" penalty.

It was the second game in a row that one of the Bruins' veteran leaders didn't know when to stop and wound up spending extra time in the penalty box as a result. On Saturday, it was Nikita Zadorov throwing an extra punch at Chicago's Alex Vlasic when the scrum was already over and Vlasic was being tied up by a ref.

The Bruins need those guys to know when something is over and it's time to just move on. They can't have them losing their cool in key moments in close games, no matter how much they think they've been wronged.

"I didn't ask Charlie yet what happened on the second one, but that's something he needs to control, right?" Sturm said. "So that's on him. Especially, you already served the penalty, or they scored, so he's got to be better than that for sure."