Shaken by their Italian Cup quarter-final elimination by Vicenza last week, Milan's season turned even bleaker with a 3-2 defeat at Piacenza after two goals by the substitute Christophe Dugarry, his first for the club, had pulled back a two-goal deficit, writes Clive White.
It was their fourth defeat of the season and a severe blow ahead of Wednesday's Champions' League match with Rosenborg Trondheim - a game they must not lose if they want to stay in the competition.
The Vicenza coach, Franceso Guidolin, watched his side draw 1-1 at Perugia to restore their one-point lead over Internazionale at the top of Serie A - and then warned about the threat of relegation.
"Our aim at the start of the season was to avoid relegation," said Guidolin, whose team is setting the pace in Serie A for the first time in their 94-year history. "Only when that aim is achieved can we start thinking about other objectives like the championship."
Alessandro Iannuzzi, a close-season buy from Lazio, scored for Vicenza after 10 minutes. Carmine Gautieri equalised for Perugia, but the point was enough to put Vicenza back on top after Inter had missed the chance to open up a bigger gap with a 2-2 draw against Cagliari on Saturday.
With the league's top two clubs due to meet next week, Juventus moved ominously into third place after defeating Bologna courtesy of Zinedine Zidane's superb free-kick.
Jorge Costa, the Porto defender whose nose was broken by the Milan striker George Weah, has spurned the Liberian player's offer of an apology and is reported to be planning to sue him for damages. Costa, who was attacked by Weah as the players left the field after a Champions' League game in Oporto, could seek damages of up to pounds 600,000.
Real Madrid ensured they will go into next weekend's big game with Barcelona as leaders of the Spanish League after beating Sporting Gijon 1-0, while two goals by Luc Nilis, his 12th and 13th of the season, ensured that PSV Eindhoven extended their lead at the top of the Dutch League to six points.
In Germany, the early-season leaders Bayer Leverkusen seized the chance to return to the top with a 4-2 win over fifth-placed Cologne.
The Belgian Robert Waseige quit as coach of Sporting Lisbon one hour after his team stumbled again in the Portuguese League, drawing 0-0 at home against Leiria. He said he "did not have strength to continue".Reuse content