Mike Vorel: Can one win swing the season? That’s for the Seahawks to decide.

SANTA CLARA, Calif. — Geno Smith’s most satisfying throw was a run.

With 18 seconds left in the fourth quarter Sunday, the Seahawks’ come-from-behind quarterback penetrated a collapsing pocket. Trailing 17-13, the 34-year-old Smith scooted up the field, before sneaking inside the left pylon for a 13-yard score. The touchdown trot provided an exclamation point on an 11-play, 80-yard siege, in which Smith completed 7-of-8 passes for 54 yards and added 29 gritty yards on the ground.

After winning a footrace to the goal line against San Francisco safety Malik Mustapha, Smith emitted a guttural roar, then ripped a pass that landed inside the northeast tunnel inside Levi’s Stadium.

“That was probably my best throw of the day,” joked Smith, who completed 25-of-32 passes and threw for 221 yards with an interception in the Seahawks’ 20-17 win. “I was just happy for the team and glad we got the win.”

It was Smith’s first such win against the 49ers as a Seahawks quarterback, and their first win against San Francisco since Dec. 5, 2021. After six straight losses to a dominant division rival, it was a past-due counterpunch. For first-year coach Mike Macdonald, it was — cue the cliché — a signature win, the kind of statement upon which a 37-year-old newcomer can build a program.

It was the kind of win that can swing a season.

It was also one game, not a guarantee.

“We get to determine that,” said Smith, when asked what Sunday’s win might mean. “I think that’s the best part: We get to determine what our season is going to be. The 49ers are a great team. Hats off to them. Much respect to them. They have great players. But we do, too. I think we just have to keep working and things will be all right.”

Things certainly look a lot better than they did a day ago — when the Seahawks sat in the cellar of the NFC West, losing five of their last six games in an extended spiral. After a bye, they released linebacker (and leading tackler) Tyrel Dodson on Monday, then announced the retirement of starting center Connor Williams in a midseason stunner.

To compound the chaos, another loss would’ve filleted their fading playoff hopes, extending the deficit in an otherwise winnable NFC West.

Now?

At 5-5, the Seahawks sit in a three-way tie with the Rams and 49ers, and can retake a division lead with a home win over Arizona (6-4) Sunday.

Maybe, someday, we’ll say everything changed for the Seahawks when Smith ran, then threw, on Sunday in Santa Clara.

But it’s only a season-swinging win if the season actually swings.

“We knew this was going to be a big game for us, because of the way we’d been playing, what our record is and where the NFC West is,” said wide receiver Tyler Lockett, who compiled two catches for 19 yards. “We knew we had to win this game and I think we did a great job of being able to take this game over and help position us to have a chance to win the NFC West.”

Added linebacker Ernest Jones IV, who led the team with 13 tackles in his third game after a trade from Tennessee: “Heck, I was in L.A. [with the Rams previously]. We couldn’t beat them in the regular season either. So for us to come down here in their spot and take a win from them, that’s big for this team. That’s big for what we have going forward. I’m going to keep saying, I’m excited about what we really can be when this thing gets rolling.”

Finally, there are reasons to think these Seahawks might start to roll.

Like wide receiver Jaxon Smith-Njigba, who contributed 10 catches for 110 yards (and has amassed 17 catches, 290 yards and two touchdowns in his last two games).

Like fellow wideout DK Metcalf, who added seven catches (on nine targets) after missing the previous two games with an MCL sprain.

Like a defense that, after unveiling Jones and rookie Tyrice Knight as its starting linebackers, limited running back Christian McCaffrey to a manageable 79 rushing yards and 4.2 yards per carry. The Seahawks also forced a 49ers punt to position Smith for the game-winning drive with 2:26 to play.

Like an offensive line that welcomed back right tackle Abraham Lucas, who had not played since Dec. 31 due to a knee injury.

“I can tell you the last five or six plays [of the final drive] I was breathing very, very heavy. It’s been almost a year since I’ve played, right?” Lucas said with a smile. “But when Geno took off and I knew he was going to score, I said, ‘Thank you, Jesus,’ and turned and walked toward the sideline. I was like, ‘I need to go get some oxygen.’”

While Lucas got oxygen, Smith went to sleep, mimicking Warriors guard Stephen Curry’s “night night” celebration along the Seahawks sideline.

In that moment, Smith also put a six-game losing streak in a habitually bitter rivalry to bed.

But how much will one win matter?

As they face another footrace to the finish, that’s for the Seahawks to decide.

“We kind of took personal not winning in six games [against the 49ers],” Smith-Njigba said. “At the beginning of the week I said, ‘I feel like it’s a playoff game. We have to go out there and win.’ I feel like our team felt that. We were all on the same page. It’s a big one for us, for sure. But we’ve got Arizona next week and we’re going to be ready for that.”

A change was made to this story to make a clarification on Geno Smith’s scoring play.