Pardew felt his side, who remain six points above the relegation zone, had deserved at least a point.
He 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."