The striker has expressed his delight after his goal against the USA sealed his country's passage to the World Cup quarter-finals
The Chelsea striker came off the bench after 90 goalless minutes in Salvador and scored his side's winning goal, as they fought off a spirited American side inspired by Tim Howard's superb goalkeeping display.
Having seen his place in Marc Wilmots' XI taken by Lille youngster Divock Origi, Lukaku revealed assurances from his coach allowed him to remain calm and finally make a telling contribution on Tuesday night.
"The coach told me I was going to come on during extra-time," he explained.
"As soon as I got onto the pitch, I knew that I would find the net.
"From my very first sprint, there was a big chance. At that moment I was very happy, because for once I did something good on the pitch.
"I perhaps put myself under too much pressure. I just wanted the team to win and for us to continue.
"With the potential we have, if we had been knocked out today, we would have all been very disappointed.
"The bench has made the difference in recent games, which means everyone is contributing."
Belgium will face Argentina in the quarter-finals on Saturday.