After taking a 4-1 lead from the first leg tie at the Camp Nou, the unbeaten LaLiga leaders were widely expected to travel to the Stadio Olimpico as a mere formality to honour the fixture as they stroll towards the semi-final stage.
However, Roma had other ideas and produced a tactical masterclass to create one of the most historic Champions League evenings in Italian history.
What made I Giallorossi's victory even more notable was the fact that the Blaugrana, famed for their 'tiki-taka', were forced into playing a direct style of football, as the desperation to break down the Serie A side became evident as the game progressed in the second-half.
"We had no response, everything went for them and for us we struggled to build our play," Valverde said after the game, as quoted by Marca. "I am responsible absolutely, I am the visible head of the team and it was down to me.
"With their pressure, it forced us to knock balls long, we became disjointed and we were not able to win the second ball. When you lose and the opposition are better then the analysis is often extreme. They (Roma) were strong, physical and we had a lot of problems.
"It is a painful defeat it is true. We all wanted to win the competition but only one can win," Valverde added. "There will be difficult games ahead but we will concentrate on winning what we can still do as so far we have won nothing.
"I hope it will not affect us but this is clearly a blow. We have important targets ahead and we will see if we can do it."