Sampdoria heaped more misery on a struggling AC Milan side with their 1-0 win in Serie A action on Sunday.
Luis Muriel scored the only goal of the game from the penalty spot on 70 minutes after Gabriel Paletta tripped Fabio Quagliarella in the box.
Milan were the better side for much of the tie though as loan signing Gerard Deulofeu looked promising early on where Mario Pasalic had a 16th minute shot blocked en route to goal.
Emiliano Viviano then tipped an Andrew Bertolacci shot from distance over his goal before Gianluigi Donnarumma did well to keep out Karol Linetty after some good approach play from Quagliarella and Muriel.
Viviano kept out a left-footed Pasalic effort from outside the area with 29 minutes played before the goalkeeper and his defence were able to clear a good ball into the area from Suso.
Suso's excellent centre on 41 minutes only needed a touch as Milan looked good value for a goal although they were unable to find a way through a resolute Sampdoria defence.
Deulofeu hit a post at the start of the second period while a counter by the hosts saw Donnarumma easily save Dennis Praet's effort.
Viviano then had to be alert to deny Sampdoria from opening the scoring as he got out quickly to clear a Bartosz Bereszynski back-pass.
Carlos Bacca fired a spectacular bicycle kick wide of the target before Milan came even closer to a goal when Suso and Bacca set up Pasalic, but he just failed to direct his powerful effort on goal.
And their failure to find an opening ultimately cost Milan as Muriel sent Donnarumma the wrong way from penalty spot in the 70th minute.
Suso responded with a poor hit on 77 minutes before Duricic fired just wide after drifting into the area.
Milan threw bodies forward in an attempt to find an equaliser, with substitute Gianluca Lapadula forcing Viviano into another good save after being put through by Suso before Jose Sosa was dismissed with 90 minutes for a second yellow card following a mistimed tackle.
Try as they might, it wasn't Milan's day as they slumped to a fourth straight defeat in all competitions.