SANTA CLARA, Calif. -- The last of the NFL's unbeatens has fallen.

Despite a spirited, fourth-quarter comeback and a wild overtime period, the San Francisco 49ers suffered their first loss of the season Monday night at Levi's Stadium, a 27-24 overtime defeat at the hands of the Seattle Seahawks and quarterback Russell Wilson.

And with that, the 1972 Miami Dolphins could celebrate again, as they remain the last NFL team to win a Super Bowl with a perfect record.

With the defeat, the Niners became the final team to lose a game this season, dropping to 8-1. They also became just the third team to win its first eight games and lose its first one in overtime in the Super Bowl era, according to ESPN Stats & Information research.

In a disappointed and emotionally drained locker room after the game, Niners coach Kyle Shanahan let his team know he was proud of it for how it fought but that the many errors it made must be corrected quickly.

"You're always disappointed when you don't win, especially when we felt we had a number of chances," Shanahan said. "I was very proud of our guys. I thought we competed very hard. Guys left it all out there. I know guys are hurting right now. I thought all three phases played hard. I thought our defense played unbelievable. I thought the offense played hard as they could but made way too many mistakes to be able to pull out a win in that game."

On a night when the Niners turned the ball over three times and allowed five sacks and 10 quarterback hits, they still had their chances to win the game. None was more tailor-made for a storybook ending than kicker Chase McLaughlin's 47-yard field goal attempt in overtime.

After hitting his first three field goals of the night, including a 47-yarder to send the game to overtime, McLaughlin had another shot from the same distance to win it in the extra period. He couldn't convert.

McLaughlin, who was signed this week to replace injured veteran kicker Robbie Gould, wasn't sure what went wrong on the kick but suspected he rushed it a bit and hit it too high, resulting in the ball sailing wide left.

"That's the life of a kicker," said McLaughlin, an undrafted rookie out of Illinois. "There's a lot of ups and downs. You've just got stay constant through it. A lot of highs and lows, and you've got to just keep moving on day by day."

After the 49ers overcame a 21-10 deficit to tie the game as regulation time expired and the teams traded punches during overtime, Wilson took over, as he so often does.

On third-and-3 at Seattle's 43, Wilson broke contain up the middle and raced 18 yards into San Francisco territory to help set up kicker Jason Myers' game-winning, 42-yard field goal.

For most of the game, the Niners had effectively limited Wilson, but they were well aware of their mistake at such a crucial moment.

"He's one of those guys that when you're rushing you've got to keep an eye on him," San Francisco defensive tackle DeForest Buckner said. "If he doesn't have a guy open, he's looking to create a play and looking for some rush lanes to open, and he got us a couple times."

More than the rare defensive miscue, the Niners' offense struggled to take care of the ball and protect quarterback Jimmy Garoppolo. San Francisco entered the game without tight end George Kittle (knee/ankle), and wide receiver Emmanuel Sanders departed in the second quarter with a rib injury that will require an MRI on Tuesday morning.

Defensive tackle D.J. Jones (groin), running back Matt Breida (ankle), defensive lineman Ronald Blair (knee) and linebacker Azeez Al-Shaair (concussion) also suffered game-ending injuries at various points.

The 49ers had three turnovers. And while they forced four from Seattle, the Seahawks managed to turn their takeaways into 21 points, while the Niners converted theirs into just seven. The Niners had allowed just 16 points off turnovers in their first eight contests.

Two of Seattle's takeaways came as a result of pressure, as the Niners' offensive line struggled to find consistency after plugging starting tackles Joe Staley and Mike McGlinchey back into the mix. Garoppolo fumbled twice on those five sacks, with the Seahawks turning both recoveries into touchdowns.

When Garoppolo did have time to throw, he didn't get much help from his pass-catchers, outside of rookie Deebo Samuel.

With 6:19 left in the third quarter, Garoppolo fired down the right sideline to a wide-open Kendrick Bourne. The throw was a bit high but should have been an easy-enough catch for Bourne that would have gone for a big gain.

Instead, the ball went right through Bourne's hands and into those of Seattle safety Quandre Diggs. At the time of the interception, the Niners were clinging to a three-point lead, but Diggs' return gave the Seahawks prime field position at San Francisco's 16. Three plays later, the Seahawks scored to take a 14-10 lead.

Bourne later dropped a would-be first down over the middle on a drive in which the 49ers had to settle for a field goal.

"Some guys made a bunch of good plays out there," Shanahan said. "But the drops were pretty obvious. We had some big ones in some big moments, and these guys have got to bounce back. You can't win the game just running the ball or just throwing the ball. You have got to be able to do both.

"We're going to have some good ones and some bad ones, but we have got to make sure we bounce back and not have one like that again."

More than maintaining an unbeaten record, a win Monday would have put the Niners firmly in control of the NFC West. Instead, Seattle now sits just one game back in the loss column and holds the early tiebreaker.

The Niners don't have much time to lick their wounds, either, as they will play the Arizona Cardinals next week on short rest before a three-game gantlet against the Green Bay Packers, Baltimore Ravens and New Orleans Saints.

"Everybody is pretty disappointed," Niners linebacker Fred Warner said. "But at the same time, this loss is not going to define us. We have an extremely tight-knit group. We've got a big game against Arizona coming up, so preparation starts as soon as we get home. We've got to make sure we're covered."