Having initially seen his header turned onto the crossbar by goalkeeper Federico Ravaglia, Lukaku was able to tap home the rebound to secure Inter a 1-0 win at Bologna on Saturday.
The result coupled with city rivals Milan only managing a draw at home to Sampdoria means the Nerazzurri have moved eight points clear at the Serie A summit.
Lukaku’s scoring feats have played a crucial role in helping Inter seize control of the title race, with the Belgian becoming only the seventh player to make it to 20 goals in back-to-back league campaigns in the club’s history.
“I’m really happy with the win today; it was a complicated game. We took a big step and need to continue down this road,” Lukaku – who was signed from Manchester United in 2019 – told Inter TV.
“It’s a great moment for me – I made the right decision coming here.
“I’ll do everything I can to help the team because I’m nobody without my teammates. The group is the most important thing. We have our aim and need to keep this up.”
Inter have a game in hand on their nearest rivals and having missed out on the Scudetto last season to Juventus, look primed to be crowned champions for the first time since 2010.
Antonio Conte’s Inter were made to work hard for the victory by Bologna, who had more possession (55.9 per cent) and 12 attempts, albeit only two of those were on target.
For Lukaku, the result was a further demonstration of the strength within the team to cope in difficult situations, though he insisted the job was still far from complete.
“We’ve all grown a lot. We deal with pressure better and turn it into positive energy,” he said.
“This helps us on the pitch and we need to continue in this manner.”
Inter have won nine league games in a row for the first time since 2007, when they set the all-time Serie A record by winning 17 on the spin.
They are next in action on Thursday when Sassuolo visit the San Siro.