Rafa Benitez bemoaned the “mistake” which cost his Newcastle United side at Turf Moor.
Burnley ran out 1-0 winners last night thanks to a 74th-minute goal from Jeff Hendrick.
Neither team had looked like scoring.
And Benitez had been preparing to make his first change when Ayoze Perez lost the ball in midfield.
The ball was worked to Jack Cork, whose shot was stopped by Rob Elliot.
Johann Berg Gudmundsson crossed to the unmarked Hendrick, who rolled the ball into an empty net.
“The thing is, it was an even game,” said United manager Benitez.
“We could win or lose. One mistake, and it happened. One mistake, and after that we pushed and had chances, but it shows in these games that you can’t give the ball away like we did.
“We made a mistake, and after that we were out of position.
“We didn’t do what we had to do. We could have done better.
“We had attempts, but in this game you have to be strong enough in defence and better in attack.
“You need more chances. They took advantage of that.”
The result saw Newcastle drop down to ninth place in the Premier League ahead of Saturday’s home game against second-bottom Bournemouth.
“Obviously, eyes are on Saturday now,” said Benitez.
“But I’m disappointed with these games, because we can win these games.
“We know the league is difficult. It’s a long race, but we have a game Saturday and we have to make sure, mentally, we are ready.
“We have to make sure we are more confident than today. We need to settle down and be ready.”
Meanwhile, Burnley manager Sean Dyche celebrated his fifth anniversary at the club.
Asked about the milestone, Dyche said: “I have had numerous anniversaries, is the fifth the new 25th?
“Respect is earned, and it has been over a five-year period here,” he said.
“We continue to work hard to progress – myself, the staff and the team.
“We’re not the market leaders, and we have to work hard for everything we can get.
“The first marker is becoming a recognised Premier League club. There’s still more work to be done.”
Dyche anticipated a “tight” game against Benitez’s United side.
“I thought before the game it would be tight,” said Dyche.
“ They wouldn’t give much away. It was how long we would have to wait to break that down.
“We had to mix our play and work hard to get that.
“They’re good side, I think. I think we edged it.
“There was a calmness to our play, which I enjoyed.
“You need moments in a game when you can disorganise a back four.
“The Premier League is a difficult place to be, and you need to get the wins however you can.
“When you’re us, you can’t go out and play fantastically.
“You have to go out and fight for the win. It’s hard to find one way.
“It’s learning that and then doing it.”