Wilson was also quick to praise the performance of goalscorers Tony McMahon, Dave Kitson and Nick Blackman, who got the third with a spectacular turn and shot.
"We defended brilliantly at times," Wilson said.
"And as the game wore on we were able to show our quality.
"The first goal was a terrific free kick by Tony McMahon. It was all caused by Jamie Murphy, who's brilliant in the way he runs at people.
"Then the delivery from Ryan Flynn at the free-kick for our second goal was top quality, and the last goal was a great move, with a great ball in from Kevin McDonald - and what a finish."
Murphy was making his debut after his switch from Motherwell and Wilson was delighted with the Scot's performance.
He went on: "I think with Jamie we've added an extra threat to the team.
"To keep a clean sheet was great because Oxford have as good an offensive threat as many teams in our division.
"Our main priority is clearly the league but it doesn't do any harm to have a run in the FA Cup because it adds to the coffers, which is important, and it's much nicer to be sat there on a Sunday waiting for your name to be pulled out of the hat, than when you've been knocked out."