New England Patriots quarterback Tom Brady criticised his side after they suffered their first loss of the season against the Baltimore Ravens.
Last season's Super Bowl champions, who were 8-0 going to Baltimore, lost 37-20 on Sunday - their first competitive defeat since December 2018.
The result leaves the San Francisco 49ers as the only unbeaten team in this year's NFL.
"Tonight obviously was not good enough," Brady said.
"When you get beaten by 17 points, that's not what we're all about. We obviously have a lot of work to do."
The Patriots struggled from the start, with the Ravens winning 17 consecutive points and gaining 198 yards to the Patriots' four in the first 15 minutes.
Lamar Jackson, the Ravens' 22-year-old quarterback, impressed with three touchdowns, while he also completed 17 of 23 passes, threw for 163 yards and rushed for 61.
Jackson's team-mate Earl Thomas said the Jackson is playing "MVP type football".
"This man is the MVP," he added. "I am right behind him. I am backing him. He makes my job that much easier. It just felt good to be part of a win like this."
Brady said the Patriots "just didn't match" their opponents, who are now top of the AFC North with a 6-2 record.
"They played a good game," the 42-year-old added. "They made a lot of plays offensively and defensively.
"When you're on the road, you've got to play well in all three phases. Offensively, we didn't do a good enough job; too many missed opportunities."