Romelu Lukaku scored on his Inter Milan return on Wednesday in a 4-0 thrashing of Viktoria Plzen, helping his side advance to the Champions League last 16 and knocking Barcelona out.

Lukaku scored Inter’s fourth goal with three minutes remaining and only four minutes after replacing Lautaro Martinez, after Henrikh Mkhitaryan and an Edin Dzeko brace had already effectively guaranteed his team second place in Group C.

Inter’s thumping victory at the San Siro, Lukaku’s first appearance in two months due to a thigh injury, has relegated Barcelona to the Europa League ahead of their match against Bayern Munich later on Wednesday.

Even if they beat group leaders Bayern, Simone Inzaghi’s side is six points ahead of Barcelona and cannot be overtaken by the Catalans due to their superior head-to-head record.

Barca’s fate was almost sealed a fortnight ago when Inter drew 3-3 at Camp Nou, following a single-goal victory for Inter the previous week.

When the group stage draw was made, Xavi Hernandez’s Barcelona were favorites to go through with Bayern, but they have only won one of their four games and collected four points.

Being eliminated so early is an embarrassment for Barcelona after a lavish summer spending spree, as well as a further strain on their troubled finances.

Before president Joan Laporta and the board used their infamous “palancas,” or financial leverage, Barcelona was 1.3 billion euros ($1.28 billion) in debt.

Meanwhile, Inter’s qualification for the knockout stages of Europe’s top club competition continues a dramatic turnaround in form for a team that appeared to be in deep trouble at the beginning of the month.