ROME • Rudi Garcia has lamented AS Roma's difficulty in finishing off opponents as the coach contemplates a tough trip to face champions Barcelona that could decide the Italian football side's Champions League fate.

Winless after three opening Group E games, Roma needed a late penalty on Wednesday to beat Bayer Leverkusen 3-2 and revive their hopes of reaching the last 16 for the first time since 2010.

The Italian Serie A team dominated the first half but their fans were put through the ringer before Bosnian midfielder Miralem Pjanic scored a tense 81st-minute spot kick to secure all three points for the hosts.

Roma's first win in the group moved them up to second place on five points, five behind leaders Barcelona, one ahead of Leverkusen and two ahead of Bate Borisov.

However, Garcia said his side's failure to kill off Leverkusen in the first half could have proved costly.

Their next game is away to Barcelona in three weeks.

"We should have gone in for the half-time break at least three or four goals ahead," said the Frenchman. "By the 50th minute, we realised how costly those errors were.

"There was a five-minute blackout at the start of the second half in which we lost all the intensity and concentration we'd had in the first.

"It will serve as a lesson for us but, thankfully, we come through unscathed."

With Roma needing a win to have any realistic chance of reaching the knockout phase, Mohamed Salah's second-minute strike settled early nerves at the Stadio Olimpico.

The hosts doubled their lead via Edin Dzeko.

But, two weeks after the sides' dramatic 4-4 draw at the BayArena, Roma were stunned in five second-half minutes when Admir Mehmedi and Javier Hernandez capitalised on defensive lapses to pull Roger Schmidt's visitors level six minutes after the restart.

Roma were shaky for the remainder of the second half.

However, they were handed a lifeline when Leverkusen captain Omer Toprak saw red late on for pushing Salah into the net as he was about to pull the trigger.

Russian referee Sergei Karasev pointed to the spot and Pjanic stepped up to beat goalkeeper Bernd Leno for a 3-2 lead nine minutes from the final whistle.

Garcia was relieved by the victory but Roma risk losing second place to Leverkusen if the German side win against Bate in three weeks' time and Roma fail to overcome Barcelona.

"Barcelona will be a really difficult game.

"If you look at the table, perhaps a draw or a defeat won't change much," he said.

"But since everyone already sees us losing that game, we will do everything we can to reverse the predictions."

AGENCE FRANCE-PRESSE