Harry Redknapp saw Lassana Diarra and Jermain Defoe score fine goals for the FA Cup holders but Defoe also missed a penalty - as did stand-in skipper Fajardo for the visitors - and the Pompey manager admitted: "I don't know if that is enough.
"We scored two good goals and played well against a very good technical side who showed in stretches what they can do. It will not be easy out there.
"Their goalkeeper made some fantastic saves including the penalty and we could have had four or five. The save from (Armand) Traore in the second half was amazing.
"But we saw enough of them to believe they could be really dangerous at home. They changed their system in the second half, pushing an extra man into midfield from the back and we couldn't get right on top of them.
"But luckily Defoe is in good form, really sharp, and Diarra is just an amazing player - one of the best midfielders anywhere. He's a fantastic talent. I couldn't see from the touchline whether their penalty should have been given but I'm told the save from Jermain was a good one
"It was a great night for supporters and they have deserved it. They have had to endure the bad times for years, watching the team struggle for results in the fourth division not that many years ago.
"Now they are seeing top Premier League and European football after such a barren spell."