Ghana international Kwadwo Asamoah was absent as Inter Milan suffered a 2-1 home defeat to Barcelona to miss out on qualification to the Round of 16 stage of the 2019/20 UEFA Champions League.
The results means, the Nerazzurri have dropped into the Europa League.
Antonio Conte's side needed a win to go through, or at least to match Borussia Dortmund’s result against Slavia Prague.
Dortmund won 2-1 at the Signal Iduna Park as the Germans took second place.
Lukaku cancelled out Carles Perez's strike but Ansu Fati’s long range effort sealed a slim win for te Spanish champions.
The goal helped Fati to break a record for being the youngest goalscorer in Champions League history at 17 years and 40 days.