Marcus Thuram made it 1–0 from a pass by Piotr Zielinski in first-half stoppage time.
Late in the match, with ten minutes left, Henrikh Mkhitaryan extended the lead to 2–0.
With three rounds of Serie A remaining, Inter's lead is unassailable at 12 points. Napoli is second, followed by Milan and Juventus.
The last time Inter won Serie A was two years ago.
Juventus is the most successful team with 36 titles. Inter's rival Milan has won the league 19 times.
