Victor Osimhen's 40th-minute opener at Deutsche Bank Park set Napoli on its way in the first leg of its last-16 clash after Kevin Trapp saved a Khvicha Kvaratskhelia penalty.

Randal Kolo Muani's red card after 58 minutes only served to further Napoli's cause before Giovanni Di Lorenzo netted to secure a comfortable lead in the tie.

Eintracht will have the chance to fight back in Naples on March 15, though it appears little can stop Luciano Spalletti's Serie A leader at present.

Kolo Muani blasted an early warning shot wide after a smart flick past Amir Rrahmani, but Napoli soon began to dominate.

Its pressure told as Aurelio Buta needlessly felled Osimhen inside the area after Hirving Lozano struck the right post, only for Trapp to dive to his right to save Kvaratskhelia's poor penalty.

Napoli did reap its rewards four minutes later, though, as Osimhen turned in Lozano's right-wing cross, with the same combination then denied a swift second by an offside flag.

Trapp parried away a swerving Lozano attempt after the interval before Kvaratskhelia wasted a glorious chance with a chip straight at the onrushing Eintracht goalkeeper, but matters went from bad to worse for Eintracht soon enough.

Kolo Muani was shown a straight red for a lunge on Andre-Frank Zambo Anguissa, and Napoli capitalised as a smart Kvaratskhelia backheel found Di Lorenzo, who curled low into the bottom-left corner to secure a two-goal cushion.