In the 38th minute of the highly-anticipated clash, De Rossi tried to break up some intricate play by intercepting Andres Iniesta's short pass to Lionel Messi.
However, in doing so, he inadvertently turned the ball into his own net in spectacular fashion.
Unfortunately for Roma, however, the Italian veteran didn't score the only own goal of the game.
Barcelona's second arrived through a 55th-minute goal from Roma's Kostas Manolas, before Gerard Pique got in on the goalscoring fun four minutes later to put the hosts 3-0 up.
Former Manchester City striker Edin Dzeko scored an away goal in the 80th minute, but Luis Suarez completed the rout three minutes from time with a left-footed strike from close range.
After the game, Roma manager Eusebio Di Francesco felt the scoreline was tough on his side and didn't reflect the Serie A club's battling performance.
He told reporters: "I think the result is too harsh given our performance, considering who we were up against.
"We made some small mistakes inside our area and were a bit slow dealing with some situations. It's a pity, but we didn't do ourselves justice. We needed to be a bit more clinical because you don't get many chances against Barcelona."
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