AC Milan lost 1-0 at Lazio on Sunday as Gustav Isaksen's 26th-minute strike sealed a pivotal defeat. The result leaves Milan eight points behind league-leading Inter with nine matches remaining.
Isaksen broke free down the wing and fired from a tight angle to open the scoring. Milan pressed in the second half but failed to convert their chances.
Inter remain atop Serie A with 68 points. Milan sit second with 60. Lazio stay ninth with 40 points after the win.