Inter Milan, touted as one of the Serie A title favourites before the season, were left with one point from their opening two matches after squandering a two-goal lead in a 2-2 home draw with Torino on Sunday.
Beaten 1-0 at Sassuolo last week, Inter appeared to be cruising when Ivan Perisic and Stefan de Vrij gave them a 2-0 half-time lead, but Torino stunned the San Siro by bouncing back with goals by Andrea Belotti and Soualiho Meite.
Perisic, a key player in the Croatia team which reached the World Cup final, gave Inter the perfect start by volleying home from Mauro Icardi's cross after seven minutes.
Inter were in total control and when De Vrij, signed from Lazio in the close season, added a second in the 32nd minute with a glancing header from Matteo Politano's free kick, it seemed to be all over.
Inter coach Luciano Spalletti complained last week that his side struggled after falling behind, but this time their troubles began when they were ahead.
Ten minutes into the second half, Iago Falque sent a long ball over the Inter defence which found Belotti who controlled it superbly to pull one back.
Then, Soualiho Meite collected a loose ball on the edge of the area, slipped past a defender and scored with a deflected shot which squeezed between Samir Handanovic and the near post.
Both sides could have won it and Perisic's rising shot was brilliantly tipped away by Salvatore Sirigu in stoppage time.