Alan Pardew thought his side were worthy of at least a point at the Liberty Stadium as Newcastle lost 1-0 to Swansea City.
After struggling to contain their hosts for much of the opening 25 minutes, the Magpies finally managed to use their physicality to knock Swansea out of their passing patterns.
Pardew's side had the better of the second half, with Papiss Cisse, Yoan Gouffran and the highly impressive Moussa Sissoko failing to convert good chances.
The manager said: "We are frustrated and disappointed we did not even get a draw as we more than deserved that.
"We sat off them for the first 20 minutes of the first half but we sorted that at half-time.
"In the second half I thought they had settled for a draw, they knew they were doing well to stay in it.
"But when we did not score in that great period we had you know any mistake can be costly and that is what happened.
"We missed two or three big chances and you cannot do that at this level.
"The goal was sloppy, it's a ball into the box, we had four defenders there and it should have been dealt with better, unfortunately it wasn't and it cost us."
Pardew also played down his apparent exchange of words with Leon Britton at half-time.
Britton had been involved in a dispute with Cisse, but the pair were making their separate ways off the field when Pardew appeared to say something to the Swansea midfielder.
Britton turned around to respond before players from both sides quickly stepped in.
But Pardew said: "There was no problem. I have nothing to say about it."