A goal from Marco Sau has given Cagliari a 1-0 lead over AC Milan in their Serie A meeting at the Stadio Sant'Elia.
The visitors came close to scoring in the opening stages when Robinho curled an effort inches over the bar.
Cagliari looked to pose a threat as Nicola Murru tried his chances with a long-range effort that sailed wide.
Mario Balotelli worked a good opening for himself when he received the ball on the edge of the box and created some space to shoot, but his powerful effort was beaten away Vladimir Avramov.
Moments later Milan should have found the back of the net. Keisuke Honda was slid through on goal by Balotelli, however, his first-time strike was pushed behind by the keeper.
In the 28th minute, the home side took the lead. A poor clearance from Marco Amelia was collected by Mauricio Pinilla, who then picked out Sau in the area. The striker took a touch, before rounding the keeper and sliding the ball into the net.
Avramov was proving hard to beat in the Cagliari goal as Honda saw the keeper palm away his close-range header.