Goals from Florian Wirtz and Robert Andrich gave the Bundesliga champions only their second win in Italy.

Roma had just two shots on target with striker Romelu Lukaku cutting an isolated figure before being replaced after 80 minutes.

Substitute Tammy Abraham spurned a golden chance to reduce the arrears in stoppage time.

After an opening half hour short on quality, Leverkusen broke the deadlock when full-back Alex Grimaldo raced on to a misplaced backpass before setting up midfielder Wirtz for his 18th goal of the season.

Hosts Roma hit back with a flurry of chances but were unable to find a leveller before the interval.

Midfielder Andrich then doubled Leverkusen's lead midway through the second half, firing into the top-left corner from long range.

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The victory stretched Xabi Alonso's side's unbeaten run to 47 matches in all competitions.

Forward Gianluca Scamacca put the visitors ahead after 11 minutes before defender Chancel Mbemba equalised with a long-range strike nine minutes later.

Both sides missed further chances, with the tie left in the balance before the second leg in Bergamo next week.