Don't look now but the NHL is back. There were a handful of meaningful hockey games played on Wednesday night -- including the reigning Stanley Cup champion St. Louis Blues playing host to the 2018 champion Washington Capitals. 

It was quite the opening night across the league, so here are five major talking points that you may have missed. 

SCORES

1. Caps spoil Blues' banner party in St. Louis

After spending a summer with the Stanley Cup, the Blues took one last skate with Lord Stanley before finally raising their first-ever championship banner to rafters at Enterprise Center. St. Louis also got to enjoy one last sing-along to "Gloria" before opening up their title defense against the Caps. 

It was a nice, long-anticipated ceremony for the Blues and their fans -- and, yes, Laila was on-hand to take it all in.

Once the puck was dropped, it seemed as though the Blues were going to pick up right where they left off. They got a goal from Sammy Blais just 53 seconds into the game and then added an Alex Pietrangelo power-play goal to jump out to an early 2-0 lead in the first period. 

But the Blues know more than anyone that it's not about how you start -- it's about how you finish. Washington rallied and eventually tied the game before forcing overtime and they sealed the victory on a winner from Jakub Vrana.

The comeback win effectively put a bit of a damper on the banner party and it wasn't the start to the title defense that St. Louis was hoping for, but a loser's point is still better than no points. 

2. Another big opening night for Matthews

Auston Matthews might have a little bit of a fire under him to start this season. He lost out on the Leafs' captaincy to John Tavares, who was announced as Toronto's first captain since 2016 just prior to Wednesday's season opener.

But even without the 'C' Matthews is undoubtedly going to score a whole lot of goals this season and he got his first two on Wednesday night. The first came off a crisp feed from William Nylander, who is wearing that fresh No. 88 and looking to have a bounce-back campaign after a pretty brutal year. If Nylander keeps dishing sauce like this, he'll have no problem raising that production.

The second also came off a gorgeous pass, this one from Mitch Marner. I mean, just look at the absolutely nasty no-look feed from Marner here. That's a $22 million connection and it's worth every penny. 

Matthews dominated and it seemed like he was making things happen every time the puck touched his stick. He was tops among Leafs forwards with a 71.4 percent Corsi share (and a 75 percent shot share) and just looked like a man possessed. He easily could have had three or four goals on opening night (again). 

Sure, it probably helped that the Leafs were playing the Senators, who looked like a complete mess out there. (Shocker, I know.) But regardless of the opponent, it was a tremendous start to the year for Matthews in Toronto.

3. Connor McDavid comes through in the clutch

Welp, it appears Connor McDavid doesn't need to be at 100 percent to put the Oilers on his back. Despite clearly being a little off his game in the Oilers' opener, McDavid was still able to wow us with late game-winner against the Canucks. With the game locked 2-2 heading into the final five minutes of the third period, McDavid got the puck on his stick and showed off that elite explosiveness and puck handling as he came through in the clutch.

It's tough to stop McDavid when he gets some steam behind him heading into the zone, but the Canucks -- and every other team --should work on not giving him such a clear highway down the middle. 

McDavid had just two shots on goal in 21:40 of ice time (and a 37.5 percent shot share in 17:25 of five-on-five play) and he didn't quite look like his best self on Wednesday, but that was probably expected given it's his first game since partially tearing the PCL in his left leg six months ago. Even as he works his way back to full strength, he's got enough pure talent to be a game-breaker in big moments. 

4. First look at the helmet rule in effect

Speaking of McDavid, he helped provide a first case study for the league's new helmet rule. You remember that new rule, right? The one that requires players to pick up their buckets (or get off ice) before making a play on the puck? Well, we got a pretty good look at how it might effect games on Day 1. 

McDavid lost his lid while Vancouver was possessing in the offensive zone and he had to pick up the helmet instead of pressuring the puck. As he struggled to get the headwear back on snugly, Alex Edler fired a slapper from the point that got the Canucks on the board for the first goal of the night.

The language of the rule leaves some wiggle room for players to be able to make an immediate play on the puck even if they've lost their bucket, so it'd be interesting to know if McDavid could have gone for the puck instead of the helmet there. In any case, McDavid didn't feel comfortable abandoning his helmet given the new rule and it had a pretty significant impact on the game.

It seems like there could be a lot of gray area similar to this situation moving forward, so buckle up (hey, it's not like the NHL doesn't already have unclear rulebook provisions that annoy fans).

5. Golden Knights throttle San Jose 

Vegas! San Jose! So much hate! So much bitterness! It's one of the NHL's most fun new rivalries. 

But Wednesday's opener in Vegas was all Golden Knights, as VGK was on the Sharks early and often. The Knights scored twice in the opening six minutes of the first period, with Mark Stone getting the party started on the power play before Reilly Smith doubled the lead minutes later. 

Stone added a helper and had a pretty big night both with and without the puck for the Golden Knights, which shouldn't come as much of a surprise. It's going to be fun to watch him hit his stride in his first full season in Vegas.. 

That assist from Stone was recorded on a goal from Cody Glass, who was making his NHL debut for Vegas on Wednesday. The sixth overall pick in 2017 looked good as he scored in his first game, delivering a beautiful far-side finish off a really nice primary dish from Max Pacioretty.

Smith had two goals. Wild Bill Karlsson had two assists. The Sharks went 0-for-5 on the power play. Vegas held a 30-9 advantage in scoring chances at five-on-five in the game. It was pretty much total domination. 

It's worth noting that San Jose was without Erik Karlsson in the game. It was announced just prior to puck drop that Karlsson would miss the game to "attend to a personal matter." There weren't a whole lot of details but Sharks coach Pete DeBoer said he didn't know Karlsson would be out until about an hour before the game, calling it "a tough spot" for the team.

Other notes