1.) The secondary stood tall and that could be a big deal.
The Ravens secondary carried them to victory Sunday — a statement we haven't been able to make around these parts for quite some time.
Whether you're partial to Jimmy Smith's smothering man-to-man coverage, Shareece Wright's frenetic run support or Eric Weddle's uncanny communication skills, Ravens defensive backs stifled the Bills in every way imaginable as they held them to 111 total passing yards and no first downs in the fourth quarter.
They did it with the greatest defensive back in franchise history, Ed Reed, looking on from the Buffalo coaching box.
This was not an elegant beginning to a new season. But the Ravens did win the kind of game they generally lost in 2015. And they did it by limiting the big strikes that doomed them too often in recent seasons.
"One of our main focuses and goals was nothing over the top of us," said Weddle, the team's No. 1 offseason addition. "That's not just one guy. That's all four of us."
Weddle delivered a big hit on his first defensive snap to hold Bills running back LeSean McCoy to a 2-yard gain. "Welcome to Baltimore!" a fan shouted from the stands.
He then broke up a pass to force a Buffalo punt on the next possession.
Beyond specific plays, teammates said, Weddle is essential to the secondary's improved cohesion.
"Man. He's a different type of guy back there," Wright said. "He's like a defensive coordinator."
Wright, meanwhile, was the star of the day with 11 tackles, including three for loss.
The Ravens lost their first three games last year on the way to a 1-6 start. By November, the preseason hype pegging them a Super Bowl contender felt like ancient history.
One 13-7 victory does not guarantee a less jagged path in 2016. But if the secondary really is this much better, that's one significant step in the right direction.
2) Coming back from knee surgery, Joe Flacco looked very much like . . . Joe Flacco.
The Ravens surely would have preferred to see Flacco take fewer hits in his first game back from knee surgery.
But the reconstructed Flacco seemed as undaunted as the old version by the jolts and bruises inherent to NFL quarterbacking.
"Tough as two-dollar steak," coach John Harbaugh said in describing his most important player.
Flacco certainly didn't play a perfect game. He turned the ball over on the Ravens' second possession when he and center Jeremy Zuttah miscommunicated on a shotgun snap.
And he got lucky in the third quarter when Bills cornerback Ronald Darby failed to pull in a potential pick-six after Steve Smith ran a different route than Flacco expected.
But Flacco also made the play of the game, checking off of a planned run and hitting Mike Wallace perfectly in stride for a 66-yard touchdown that would prove decisive.
After an offseason of speculation about how their quarterback would deal with the first major injury of his career, the Ravens had to take comfort seeing how little had changed. Flacco was still Flacco.
3) The offensive line needs to improve in a hurry.
Flacco's protectors did him few favors, allowing four sacks and nine quarterback hits.
Add in a cluster of early penalties and a 3-yard-per-carry average on the run and this was not a reassuring performance by a unit the Ravens overhauled in the offseason.
"We sure want to protect our quarterback better than that," Harbaugh said.
With projected starter John Urschel on the inactive list, the Ravens started two rookies, tackle Ronnie Stanley and guard Alex Lewis, on the left side of line.
Stanley committed one of those pesky penalties, a false start.
But he and Lewis were no more to blame for the shoddy performance than their veteran colleagues.
Zuttah barely got a hand on Bills linebacker Jerry Hughes as he rushed up the middle to sack Flacco just before halftime.
Marshal Yanda, the best guard in the league, also played an uncharacteristically sloppy game, committing two penalties and allowing one of those jarring second-half hits on Flacco.
It's entirely possible this unit will look better after a few weeks of polishing against defenses that aren't as blitz-happy as Rex Ryan's Bills. But the line was the greatest area of concern to emerge from the opener.
4) Flacco has a niftier set of toys to play with.
Even before he got hurt last year, Flacco's greatest weapon — his deep arm — was largely neutralized by the paucity of downfield targets on the Ravens roster.
First-round pick Breshad Perriman was supposed to fill that gap after Torrey Smith departed in free agency. But that never happened because of a knee injury that would not heal.
Fans spent the better part of a year grumbling about Perriman's fragility as an injury that was supposed to be minor lingered on and on. Such is life in the what-have-you-done-for-me-lately NFL, and Perriman understandably took it hard.
Well, he celebrated his long-awaited debut with a superb leaping catch for 35 yards late in the first quarter Sunday. That one play reminded everyone in the stadium why the second-year wideout was such a tantalizing prospect in the first place. Perriman is more than just a straight-line scorcher. He'll go up and fight for the ball.
But the Ravens weren't content to rely entirely on Perriman's return to health. They also added a proven deep threat in Wallace, who quickly rewarded their investment by gliding past Bills safety Duke Williams for that 66-yard touchdown.
"We don't win the game without those two plays," Harbaugh said.
Which is basically to say the Ravens would not have won it in the second half of last year, when Kamar Aiken was their No. 1 wide receiver.
Now, they have Wallace, Perriman, Steve Smith and Aiken, not to mention tight end Dennis Pitta. If all stay healthy — a big if — it could be the most dynamic group Flacco has ever thrown to.
5) Terrell Suggs' return from a second torn Achilles is a work in progress.
Suggs wasn't the focus, not on a day when the defense dominated the Bills overall. He managed a sack in his first game back after missing the last 15 of last season.
But he did not immediately look like the Suggs of 2014.
"It's definitely still coming," he said. "This was my first live action in a year. You can't really count the preseason games. I only got a couple of series. … I'm going to just continue to chop wood. You can always get better."
Suggs generally lined up in his familiar spot on the opposing quarterback's blind side. But he posed little threat to Tyrod Taylor for most of the game, even when he was blocked one on one.
In his prime, Suggs was a true every-down player, as smart and steady against the run as he was explosive against the pass. But he reacted sluggishly when the Bills ran to his side, and Harbaugh gave him frequent breaks even though the team's other veteran pass rusher, Elvis Dumervil, was on the inactive list.
Suggs, who'll turn 34 next month, has spent the last month proclaiming how young he feels and how confident he is that he can regain his Pro Bowl form.
It's too early to say he's wrong. But it's possible that after two Achilles tears, his body cannot answer his mind's call, at least not all the time.