Oxford United: Karl Robinson 'anger' over Alex Mowatt sending off at Portsmouth

Portsmouth's Nathan Thompson (right) went to ground after he was pushed in the face by Oxford's Alex Mowatt (left)

Oxford United manager Karl Robinson has labelled Portsmouth midfielder Nathan Thompson's behaviour "unacceptable" in their 3-0 defeat at Fratton Park.

Thompson ran to goad Oxford's Alex Mowatt after he missed a second-half penalty when the score was only 1-0.

Mowatt was sent off after pushing Thompson in the face, but the Pompey player was not shown a second yellow card for his part in the incident.

"I'm angry," Robinson said. "The referee has cost us the game."

Oxford had to play the remaining 28 minutes with 10 men, and Portsmouth made sure of all three points thanks to Brett Pitman's two close-range goals.

Thompson had been booked in the first half by referee Charles Breakspear for a foul on Oxford forward James Henry, but escaped further punishment in the melee after Mowatt's penalty miss.

"He's run fully 20 yards to stand in Alex's face and goad him," Robinson told BBC Radio Oxford after his first game as Yellows manager.

"I've not seen that for a long, long time. That's a booking, he was booked in the first half and apparently he's told my players on the pitch that he's booked him then too."

Breakspear actually booked Portsmouth goalkeeper Luke McGee for dissent instead of Thompson.

"What Nathan did today wasn't acceptable on a football pitch," Robinson added. "If one of my players did that, I'd tell them the same and reprimand them accordingly."

Portsmouth assistant manager Joe Gallen admitted he did not see the aftermath.

"I looked up from the touchline to see Nathan sprawled on the floor," he told BBC Radio Solent.

"It's difficult for me to comment as I was just thinking how relieved I was at the time that the penalty had been missed."