Walter Mazzarri celebrated victory against his old club as Torino won 1-0 at home to Inter in Serie A on Sunday.
Armando Izzo's deflected header in the first half was enough to give Torino their first win of the year, while problems are mounting for Inter coach Luciano Spalletti, who saw Matteo Politano sent off for dissent late on.
Ivan Perisic was benched after it was announced pre-match he has put in a transfer request amid speculation Premier League side Arsenal are trying to complete a move for the attacker.
Defeat for Inter leaves Spalletti's side third in Serie A, while Torino move into the top half of the table.
Inter should have taken an early lead but Lautaro Martinez fired wide from close range after Dalbert raided down the left wing to pull back a low cross.
But Torino took the lead against the run of play in the 35th minute when Cristian Ansaldi's deep corner was headed home by Izzo, a deflection off Danilo D'Ambrosio sending the ball looping over goalkeeper Samir Handanovic.
Andrea Belotti wasted two chances to extend Torino's lead early in the second half, while Radja Nainggolan hammered a drive over the crossbar at the other end.
Politano went closest to equalising but a day of disarray for Inter ended with the substitute dismissed for arguing with referee Fabio Maresca over the official's decision not to award a foul against Ola Aina after the midfielder went to ground too easily.
What does it mean? Inter stumbles continue without Perisic
Croatia star Perisic was expected to start against Torino, but pre-match it was confirmed by general manager Beppe Marotta he has put in a transfer request. Failing to score in both of their Serie A matches since the mid-season break shows Inter cannot afford to lose Perisic cheaply.
Nkoulou keeps Inter attack quiet
Torino's back three all excelled but it was Nicolas Nkoulou who shone the most despite Izzo proving the matchwinner. Recovering after taking a heavy blow in the back of the head from a clearance made by a team-mate showed his fortitude for battle.
Icardi anonymous for Inter
Inter captain Mauro Icardi is one of the most dangerous strikers in world football but he does rely on service. Perisic's absence restricted the Nerazzurri's creativity and Icardi did not have a sniff of goal. Among Inter's problems is that the Argentine offers very little outside the penalty box.
Inter host Lazio in the Coppa Italia quarter-finals on Thursday, with Bologna going to San Siro three days later in the league. Torino's next game is at SPAL on Sunday.