Inter had not won against Juventus since September 2016, but on Sunday night there was a trend break.
Juventus did not have a chance when the blue and blacks took a comfortable 2-0 victory.
Inter took the lead already in the twelfth minute after the former Juventus star Arturo Vidal ran into the penalty area and nodded in 1-0.
After that, there was real Inter-dominance in both goal chances and ball possession.
At the beginning of the second half, Nicolò Barella was able to run free and double the Milan team's lead with a rock-hard finish.
Kulusevski came in with half an hour left
Juventus was in dire need of change and launched a triple change with half an hour left to play.
Swedish star Dejan Kulusevski replaced Aaron Ramsey and took a place on the right in midfield.
The BP product failed to untie the knots in the Inter-Armed Forces and accounted for an overall pale effort.
Inter's Lautaro Martinez had a chance to level the score as he slipped, but the shot went wide.
After the victory, Inter goes up alongside city rival Milan at the top of the Serie A table, on 40 recorded points.
But the red and blacks have one game less played and can deduct when they face Cagliari on Monday.
Juventus are in fifth place in the table with 33 points.