The attacking player delivered some teasing balls from the right as Hibs dominated the first half in Andorra and his shot bounced off the post before Daniel Mackay knocked home the winning goal in a 2-1 victory.
Campbell came in for his first Hibs start in two years after coming off the bench in last week's 3-0 first-leg win.
After Hibs progressed to a meeting with Rijeka in the third qualifying round, Ross said: "He deserved to play, he has had a good pre-season. He had a good loan spell at Edinburgh City last year.
"He had a taste of first-team football a couple of years ago when Neil (Lennon) was still manager, and has gone out on loan.
"We had five players starting who are 22 and under which is a young team to play in Europe.
"I am pleased for Josh because he is a Hibs fan, desperate to play for this club and desperate to do well for it.
"He gave himself every chance of being involved in the upcoming games as well."
Hibs fell behind in the 70th minute after goalkeeper Matt Macey had made some decent saves, but they led within six minutes thanks to goals from Jamie Murphy and Mackay.
Ross said: "Really pleased to win the tie this evening and pleased to progress overall comfortably.
"I was a little bit frustrated with bits, and obviously disappointed to go behind, but our reaction was very good, and winning games is an important habit.
"We felt as if we had much more control than we did last week, particularly first half, and a bit frustrated we didn't take any of the opportunities we created first half.
"The longer the game goes they threw caution to the wind and they have technically good players.
"In some way, if you win the tie, it was good for Matt to get some action because you need him to be sharp for the weekend."