Watford boss Malky Mackay was aggrieved his side were not awarded a penalty during the 2-1 defeat at Peterborough.
The Hornets were desperately unlucky to see loud penalty appeals waved away by referee Karl Evans when Danny Graham was clattered to the floor by keeper Joe Lewis.
Mackay said: "I thought we had an absolute stonewall penalty which would have made it 1-1 going into half-time.
"The goalkeeper even admitted to the forward that he gave a penalty away, the linesman admitted to me that there was contact made so I cannot believe it."
John Eustace did cancel out Lee Frecklington's volley but the Hornets were undone by Exodus Geohaghon's first league goal 12 minutes from time.
