Newly promoted Serie A team Lecce forced Juventus to a 1-1 draw at Stadio Val De Mare on Saturday, throwing the table open for Inter to go top.
Juventus, playing without Cristiano Ronaldo scored first via a Paulo Dybala spot kick in the 50th minute. But six minutes after Lecce equalised from the same penalty spot, with Marco Mancosu scoring.
Inter will host Parma later in the day and may well seize the leadership if they win.
Juventus are now with 23 points after nine matches while Inter have 21 points in eight matches.