Remember when the 49ers-Seahawks rivalry meant something?

Well, I can't say that the country was treated to a great game on Thursday Night Football. The Seahawks dominated the 49ers, but we can at least say that the outcome of the game has the potential to have big implications for both clubs.

Seattle bounced back after two embarrassing, frustrating fourth quarter collapses over the last two weeks to overwhelm a hated division rival. It also took an important psychological step in getting its season back on track.

Meanwhile, the Niners' season looks to be on the verge of collapse. They dropped to 2-5, and there are hints and rumors of potential "big changes" in store for a team that's already had plenty of that over the last six months.

Two teams that had one of the most exciting rivalries in recent years are now moving in vastly different directions.

What this game told us about Seattle.

1. Marshawn Lynch looked like Beast Mode again

Coming into this game, Marshawn Lynch had rushed just 55 times for 182 yards in four games -- 3.3 yards per carry and 45.5 yards per game -- and had missed the previous two matchups with lingering calf and hamstring injuries. There has been talk in Seattle of Lynch falling off the inevitable "running back cliff" where a steep decline in performance doesn't typically come slowly, but suddenly. Some of those fears were allayed on Thursday night as Lynch ran all over the Niners' defense to the tune of 122 yards and a touchdown.

Importantly, Lynch set the tone early. On Seattle's first drive of the game -- a 12-play, 61 yard drive that ate up over six minutes in clock -- the Seahawks handed it to Lynch nine times, culminating in a touchdown run where he dove over into the end zone for pay dirt. Lynch's 27 totes were the most he's carried the rock for Seattle going back to its playoff win over New Orleans in January 2014, a span on 29 games. This game was about the Beast, and Lynch featured heavily as the Seahawks ran the ball 41 times.

After the game, a chorus of Seahawks players sang Lynch's praises, and all had a similar refrain.

"Without him, our offense can't function," said safety Earl Thomas. "It definitely starts with him. The play-action game starts with him. Even the read-option game, with Russell, it starts with him. We go as he goes."

Cornerback Richard Sherman echoed Thomas' praise of Lynch. "On defense, we try to make our stops and get off the field, but with the offense, we go as [Marshawn] goes. He keeps us off the field, he keeps the first downs going. He keeps us off the field on third down. As long as they're on the field, and they're running time off the clock, we're resting. I think that anytime you have a great combination of a run game and a great defense playing well, you're going to be successful."

"That is Seahawks football," said Doug Baldwin. "We go with Marshawn. He leads the way. The style in which he runs, the style in which he leads in the huddle, that's what's important to us. That's what helps us get to where we want to be. We'll go as far as he takes us."

Getting Marshawn Lynch back to looking like the player that's helped lead Seattle to two straight Super Bowl appearances was important for the Seahawks, and it could prove to be big going forward.

2. Seattle's defense looked fearsome

The Seahawks pass rushers don't get as much play as some of the superstars in this league, but Michael Bennett and Cliff Avril dominated this game from the defensive side of the ball. The duo combined to collect five sacks, seven quarterback hits and Avril forced a fumble that the Niners recovered. They were constantly harassing Colin Kaepernick and rarely gave him a clean pocket to throw from, and the result was the lowest passing yardage total (146 yards) for the 49ers since the 2006 season.

Richard Sherman locked down Torrey Smith for the entire game, shadowing him all over the field for 42 snaps. Smith's stat line for the evening: zero catches for 0 yards on one target.

The Seahawks are not out of the woods in terms of getting all their issues on defense fixed, but this was a good game to get them back on the right path.

3. The Seahawks finished a game!

Much had been made about the Seahawks' struggles to finish games this year after the collapses in Cincy and against Carolina. But they got the job done in San Francisco by closing this one out after carrying a 14-point lead into the final frame.

On offense, the Seahawks only put up three points in the second half, but when their defense gave them the ball with 3:05 remaining, they did what they were supposed to do: ran the clock out. Seattle's offense -- without a healthy Lynch -- had been stagnant at times and particularly inept late in games of late, and they'd clearly missed Lynch's punishing style that has traditionally helped the Seahawks finish even with small leads in the fourth quarter. Three Lynch runs for 19 yards and a Russell Wilson pass to Tyler Lockett closed this one out, and Seattle got that fourth-quarter monkey off its back at least for one week.

4. The Seahawks are not out of this thing yet

Seattle now sits at 3-4 and is still within striking distance of the Cardinals, who it still is set to face twice this season. The Seahawks have 10 days of rest, then will travel to Dallas to take on Matt Cassel, Christine Michael and the Cowboys before heading into their bye week. If Seattle can win that game on the road, it will improve to 4-4, and then gets three straight home games (Cardinals, 49ers, Steelers) to right the ship and make a playoff run.

It's way too early to say the Seahawks "are back," but after getting this much-needed win in San Francisco, it's also too early to count them out.

As for the Niners ...

... this game caused things to go the other direction.

1. The 49ers' offense regressed badly

Colin Kaepernick came into this matchup playing his best football of the season. In his previous two games (a close loss to the Giants and a win over the Ravens), he had completed 39 of 62 passes (63 percent) for 604 yards, four touchdowns and no picks. Some of the pre-game chatter was about an improved player, potentially poised to make a jump back to where he should be and where he used to be. That didn't happen.

Kaepernick was wildly inaccurate (or, maybe just tossing too many passes away) from the start of the game. He nailed his trainer in the head with a throw that he sailed into the sideline and generally did not look like he was under control or in command. He didn't get much help from his offensive line, of course, and was also sacked six times. Kaepernick finished with 124 yards on 24 attempts (5.1 yards per attempt), and the Niners punted nine times while grabbing just eight first downs. The last time the 49ers had more punts than first downs was back in 2007.

Basically it was an awful offensive performance. Obviously.

2. San Francisco looked uninspired

More worrisome though might be the way the entire 49ers team played. Even in a rivalry game like this against the Seahawks, at home, they didn't seem to bring much energy to the field. As Colin Kaepernick put it post-game, "they are talented and we didn't match that intensity today."

Jim Tomsula said much of the same. "That game today was not what we want. It was not acceptable. We did not play well. We don't have an excuse."

Torrey Smith didn't mince words either, tweeting "Unacceptable....that was sorry."

The Niners went into the game as home 'dogs and have had their fair share of struggles this season, but the team and its coaching staff can't be happy with the apparent lack of fight they showed against a similarly struggling Seahawks team.

After the game, beat reporter Matt Maiocco said that it was such a bad loss that it may spur some "big changes" for the Niners going forward. He was vague in his reporting, so we'll have to see what those changes might entail, but it is very possible that this could end up being Colin Kaepernick's final season in San Francisco.

3. The future of Colin Kaepernick is a big question mark

When I talked to David Fucillo, the excellent editor over at Niners Nation, this week, he mentioned that this game could be a big factor in to the long-term future of Colin Kaepernick in a 49ers uniform. Kaepernick came into this matchup at a bit of a cross-roads -- he's struggled mightily this season but had turned it around of late, and had a chance at a signature win against a team that has mostly given him fits over the years. That did not happen.

Much in the way that last year's Thanksgiving defeat at the hands of the Seahawks spelled the beginning of the end for the Jim Harbaugh era in San Francisco, could this loss have a similar impact on Kaepernick? Obviously, it's been a longer time coming for Kaepernick, and the team gave him an easy-to-get-out-of contract for a reason, but if Kaepernick doesn't turn things around quickly, he could be finding himself on a new club come 2016. How weird.

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Together, these two teams had represented the NFC in the Super Bowl in each of the last three years, and both were now experiencing seasons on the ropes. But, while it was just another sloppy, relatively ugly Thursday Night Football division-rivalry grudge match, the outcome could end up reverberating loudly for both teams as the season goes on.

It could be a turning point for the Seahawks, who seemed to bounce back from trouble and regain at least part of their swagger, as several players alluded to after the game. Seattle faced some early-season adversity last year as well before winning nine of their final ten games, and that experience could pay dividends for them now.

At the same time, the game had an opposite effect on San Francisco. Given a shot at sending the Seahawks to the NFC West cellar, the 49ers came up short at home, and the loss has fans asking a lot of questions.

Since the 2014 NFC Championship Game -- "The real Super Bowl" that year -- these teams have been on divergent paths, and owner Jed York's decision to run Jim Harbaugh out of town has unquestionably blown up in his face. Jim Tomsula was dealt a tough hand after the retirement of Justin Smith, Patrick Willis, Chris Borland, etc., but teams tend to take on the personality of their head coach. You can't help but wonder how different things would be if the front office had simply learned to get along with the guy that had quickly turned the Niners into one of the most intimidating and confident groups in the NFL.