The League One promotion hopefuls allowed Charlie Wyke to score four headers from Aiden McGeady crosses in a poor defensive display at the Stadium of Light.
They actually showed some promise on the ball, but twice saw second-half penalties saved. Even had they beaten Lee Burge from 12 yards, it would have made little difference at that stage.
“From our point of view it's not good enough,” said a downbeat Moore. “It started poorly and we got back into the game but we gave an own goal away.
“We had two penalties a couple of weeks ago (at Lincoln City) that Ellery (Balcombe) saved and this time we had two saved. It was our opportunity to get back into the game but it just wasn't good enough.
“All four goals were avoidable really.
“They were three free headers in the box and an own goal (a Wyke header deflected off a defender). It tells the story of the game.
“It's back to the drawing board and back to work on Monday.”
Wyke completed his hat-trick inside 31 minutes but as soon as Doncaster pulled a goal back in the second half – a Taylor Richards shot hitting the post and bouncing in off the back of goalkeeper Burge – the Black Cats went down the other end and scored a fourth.
“In the second half I thought we had them penned in and it was almost like attack v defence but they were able to sit in because they had the lead,” said Moore
“Had we scored at those times it might have been a different game but to concede again was disappointing.
“We found the spaces but when you give goals away like that... I always felt we'd score, it was just keeping the back door shut.
“They were basic, elementary mistakes.
“The damage was done giving them those goals in the first half,.
“We were really slow starters. We grew into the game and made a fight of it but conceded again shortly afterwards.
“Yes, we made more of a fight of it and had two penalties but it's about putting in performances over 90 minutes. Monday can't come quickly enough for me.”
Doncaster's next game is due to be against Accrington Stanley on Tuesday but it could be pushed back 24 hours if the Lancashire side are successfully able to play their game at Lincoln City, postponed on Saturday, on Sunday evening.
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