From an earlier game, but little has changed: The Seahawks defense had its way with the 49ers. / Drew McKenzie, Sportspress Northwest file

The 49ers are in such a state of disrepair that it would be easy to dismiss any victory over them as truck over pavement. But Thursday night in Santa Clara, CA.,  was a bigger deal than the 20-3 outcome indicated because the Seahawks had been engaged in a mild form of self-destruction — losing games exactly how they usually win them.

They had to overcome a bad home loss, a short work week, a teammate’s car accident and the nagging thought that the swagger that defined them was slipping away for reasons that no one quite understood. Hey, 2-4 is 2-4, no matter the closeness of outcome or quality of opponent.

Because it was mission-critical, they had to bang hard on someone. Just happened to be the 49ers.

“Too much story to tell yet; too many things to happen,” said QB Russell Wilson of the prospect of another failure that would have ruined the season. “We had to choose and we chose to believe, in ourselves and each other.”

Hackneyed as it sounds, Wilson was right: What had to happen, happened.

On the first drive, they loaded up on RB Marshawn Lynch and pounded with straight-ahead, I-formation, Midwest football that would have made Woody Hayes proud. On the defense’s first series, they bull-rushed DEs Michael Bennett and Cliff Avril so ferociously that Niners QB Colin Kaepernick for the rest of the game played scared, never once choosing to run the ball.

After that, the 49ers were game-dead.

The Seahawks imposed their will. Like old times.

“It was nice to see us run the ball with authority,” said a satisfied coach, Pete Carroll. “It was a normal Seahawks night.”

It was normal because Lynch ran for 122 soul-crushing yards, clearly his healthiest, most inspired game of the year. At his best, Lynch is a marvel. After that remarkable first series of 80 yards in which he carried nine times for 38 yards, including the final yard for a touchdown by going airborne over the goal line, he was so wound up that the national TV cameras caught him on the sidelines vomiting in a bucket.

“That first drive got him going,”  Carroll said. “It gassed him a little bit. Marshawn was really solid. It was really great to run the football like that, hammering it in.”

The 49ers over the years must have learned to hate tackling the guy.

And they must hate blocking DE Michael Bennett, who had 3½ sacks and undoubtedly worked his way into Kaepernick’s nightmares.

“He’s such a great disrupter,” Carroll said. “He was causing problems even when he wasn’t gettting to the quarterback.”

Kaepernick was sacked six times, the 49ers had 142 yards of offense and more punts (nine) than first downs (eight). Most important, the Seahawks smothered the 49ers late, in contrast to the four losses in which the Seahawks gave up fourth-quarter leads.

Carroll was so upset about that disruption of team order that he was almost indignant talking about the failures.

“That was normal,” he said of the shutdown. “That’s the way we’re supposed to do it. Not making a big deal about that. We should be finishing like that.”

But it was a big deal, because they had not been finishing off teams. After the galling failures late against two good teams, Cincinnati and Carolina, Carroll was desperate to put the universe as he sees it in proper order.

The victory was a start, not a finish, particularly when Wilson spoiled the feel-good buzz with two interceptions, including a horrendous deep chuck to WR Jermaine Kearse in the third quarter that was into double coverage and had no chance.

“The last time he did that was against Arizona in his first game,” Carroll said. “I was really disappointed in that long ball. We don’t need to throw ball like that.”

Not everything was fixed with the win. But an important thing was remembered: How to impose will.