Kyle Shanahan was left to rue too many mistakes from the San Francisco 49ers after their unbeaten run was ended by the Seattle Seahawks in dramatic fashion.
The Niners became the last NFL team to lose their perfect record this season on Monday, going down 27-24 in overtime at Levi's Stadium to move to 8-1.
Jason Myers' 42-yard field goal won a pulsating contest, while the Seahawks' MVP candidate Russell Wilson completed 24 of 34 passes for 232 yards, threw one touchdown and an interception.
Chase McLaughlin missed an opportunity to win it for the Niners with a 47-yard field goal in the extra period, before Myers stepped up to inflict a first loss of the season on San Francisco.
Seattle are hot on the heels of the Niners at 8-2 in the NFC West, and Shanahan felt his side only had themselves to blame for slipping up.
"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."
The Niners also lost Emmanuel Sanders (rib), D.J. Jones (groin), Matt Breida (ankle), Ronald Blair (knee) and Azeez Al-Shaair (concussion) to injury.