The Belgium international's performances at the spearhead of the attack have helped propel the Nerazzurri into an eight point lead over AC Milan at the Serie A summit, and they also have a game in hand.
With just ten league fixtures left to play, the Italian title is Inter's to lose.
Lukaku failed to convince Manchester United supporters during his two-year stay in North West England, but he has sent a stark message to his most vehement of critics in 2020/21.
Inter recorded a 1-0 win over Bologna on Saturday afternoon courtesy of Lukaku's first-half strike, which took his tally to 20 league goals for the season.
However, that was not the only landmark he reached in the process of consolidating Inter's healthy Serie A lead.
The strike took his total tally for Inter to 60 goals, eclipsing Ronaldo Nazario's return in the famous blue and black strip.
Not only has he surpassed the Brazilian legend, he has achieved that feat in 13 fewer games.
Ronaldo racked up 59 goals for Inter in 99 appearances, but Lukaku has hit the 60-mark in just 86 outings.
While Inter's current number nine may not possess Ronaldo's level of panache or ability to bamboozle defenders with the ball at his feet, the stats suggest he carries a superior threat in front of goal.
And if that equates to a Serie A title for Inter, which looks inevitable at this late stage in the season, then Lukaku is destined to go down as one of the most revered forwards in the club's history.
Ronaldo, a two-time Ballon d'Or winner and World Cup winner, will be remembered as an all-time great by the wider footballing audience, but he never won a league title during his five-year stint with Inter.
If the 27-year-old continues to score at his current rate, he will eventually overtake Christian Vieri's return of 122 goals in 190 games.
He's also just six goals shy of Zlatan Ibrahimovic, who scored 66 in 117 Inter games at a rate of one goal every 147 minutes.
By comparison, Ibrahimovic's arch-nemesis in Italy this season has scored one goal every 117 minutes in less than two years at the San Siro.
Lukaku is well on his way to legendary status at Inter.