Roma struck twice in the second half to beat CFR Cluj and claim their first victory in the Champions League this season.
Philippe Mexes put the Italians ahead in the 69th minute before substitute Marco Borriello doubled the lead two minutes later.
Cluj's Ionut Rada reduced the arrears with 12 minutes remaining, but Roma held on.
The Giallorossi, who lost their opener at Bayern Munich, were dreadful in the first half-hour and were lucky not to be 2-0 down early in the second half.
Cluj's Lacina Traore hit the crossbar after 31 minutes played and the Ivory Coast striker could not believe his misfortune after his bullet strike rebounded off the post in the 52nd minute.
The win lifts Roma to second in Group E, level on three points with Cluj and one point behind leaders Bayern Munich after two games played.
Cluj dominated possession early on but could not make it count.
Traore thought he had put them ahead after 31 minutes but his left-footed strike from 15 yards hit the crossbar with Roma goalkeeper Bogdan Lobont already beaten.
It was a wake-up call for Roma, who had the first chance soon after.
Daniele De Rossi set up Mirko Vucinic and his angled shot from the edge of the area forced Cluj goalkeeper Nuno Claro to make a save. Shortly after, Claro did well to turn away Francesco Totti's free-kick.
On the stroke of half-time, Nicolas Burdisso latched onto Totti's cross and his header was saved by Claro.
In the 52nd minute, Traore's bullet strike from distance struck the far post as Cluj began the second half in confident fashion.
Roma pressed forward and broke the deadlock after the hour mark.
David Pizarro's low corner found Mexes inside the area and he fired past Claro.
Cluj had little time to react as Roma struck again soon after.
Borriello got behind De Rossi's pass and his beautiful volley went into the back of the net.
The visitors never gave up hope and reduced the deficit with 12 minutes remaining as Rada nodded Culio's free-kick past Lobont.
Roma were forced to defend as Cluj went in search of the equaliser.
With two minutes remaining, Lobont did well to punch away a dangerous strike from Dica.
Roma boss Claudio Ranieri know his team almost threw away two points at home to Cluj as the post came to their rescue.
"I am satisfied with the performance, which was important after the win over Inter, as we had to kick-start our Champions League campaign," Ranieri said. "We played pretty well and knew the difficulties we were facing, so we moved the ball around quickly.
"It's a shame we didn't quite get the finish we were looking for and fortunate that Traore opted to shoot rather than pass, so he let us off the hook.
"There was a lapse in concentration on the set play. We knew that lad was good in the air, as he also scored against Basel. We shouldn't have allowed those three counter-attacks, but thankfully the woodwork was kind to us. We knew Cluj would play on the counter this way, so allowing them three opportunities was a bit much.
"We kept the initiative throughout and dominated possession, but had to be careful as Cluj are excellent on the counter. We could have done without the Cluj goal, as that opened the door and made it very tense to the end.
"We had pace and depth, but nobody who could put the ball in the back of the net. Borriello and Adriano gave us that figure. This team was accustomed to playing without a centre-forward and all the midfielders pushing up, so they became impossible to mark.
"Putting more strikers on can leave us a bit stretched, so I seek unity more than the quality of those many forwards. They have great talent, but we cannot always play with that many strikers. Adriano needs playing time and sadly I cannot always give it to him. He's a great champion clearly lacking match fitness and pace, but he fought for Roma and we should've passed him the ball more often, as he was left a little isolated.
"Slowly we will all get to know each other and I'm happy with the work he does in training."