Robinson, 31, said: "We are all fighting for our shirts because you do not know who is watching.
"You have got to be professional and get on with your job. It was a great shift by the lads.
"The FA Cup is special and these ties are always difficult. When you play against lower league teams they always give you a game.
"We managed to grind them down and get the right result. We got two early goals in the second half which saw them off.
"The scoreline was a fair reflection of the game. I was more pleased with the clean sheet than the score as we have not been able to keep one in the league."