AC Milan, Villarreal and Nice reached the knockout stage of the Europa League after posting wins on Thursday in the penultimate round of the group stage.
Juventus closed on their 29th Italian title with a 1-0 win over AC Milan thanks to Arturo Vidal's second-half penalty on Sunday.
Brazilian Kaka helped AC Milan thrash Boca Juniors 4-2 to win the Club World Cup.
Italy and AC Milan forward Antonio Cassano will be out for a "few months" and needs heart surgery after falling ill at the weekend, the Italian champions said on Wednesday.
AC Milan coach Carlo Ancelotti promised to restore Europe's honour by beating Boca Juniors in Sunday's Club World Cup final.
Substitute Alexandre Pato netted a superb winner after Robinho had opened the scoring using the top of his arm as Serie A leaders AC Milan ground out a precious 2-1 win at Chievo on Sunday.
AC Milan took their time but eventually eased past bottom side Novara 3-0 to stay on the tail of Serie A leaders Juventus on Sunday as Udinese and Inter Milan also won.
A summary of the opening night's matches in the Champions League.
Two Wayne Rooney headers midway through the second half gave Manchester United a slightly fortunate 3-2 win at AC Milan in their pulsating Champions League last 16 first leg on Tuesday. Seven-times champions Milan, who had never lost to United at home or over two legs, were quickly ahead when Ronaldinho's volley deflected in off Michael Carrick following a free kick from former United midfielder David Beckham.
Zlatan Ibrahimovic has yet to declare eternal love for AC Milan but he is already striking blows at former club and last term's treble winners Inter Milan.
Clarence Seedorf will need to tap into all the experience he gained as the only player to win the Champions League with three different clubs if his AC Milan side are to get past Atletico Madrid into the quarter-finals.
Sporting marked the final home game of coach Ruben Amorim's reign in stunning fashion as Viktor Gyokeres' hat-trick saw them come from behind to thrash Manchester City 4-1 and maintain their superb start to the Champions League on Tuesday.
The Argentine teenager has been out of action after he tore a thigh muscle during the Champions League match against Chelsea
Roundup of the Champions League match played on Tuesday.
Last week's Champions League first leg quarter-final in Lyon ended goalless, leaving Milan needing a victory as a scoring draw would send the French side through on the 'away goals' rule.
AC Milan striker Ronaldo suffered a thigh injury in training on Friday and is doubtful for Sunday's Serie A match with Fiorentina.
Manchester United will carry the hopes of an all-English Champions League final with them this week when they host AC Milan and Chelsea face Liverpool at Stamford Bridge.
Midfield mastery holds the key in the European Cup Champions League final.
Lionel Messi needs one more goal to break the Champions League season record of 12 goals, as title holders and favourites Barcelona visit AC Milan on Wednesday with the odds firmly stacked against the injury-hit Serie A team.
Goekhan Inler took advantage of dreadful AC Milan defending to give Udinese a deserved 1-0 win in their Italian Cup quarter-final on Wednesday.
Serie A leaders AC Milan dropped two precious points by drawing 1-1 at Catania on Saturday in another match featuring controversy over a goalline clearance.
David Beckham wants to stay at AC Milan after his loan from Los Angeles Galaxy finishes on March 9, the Serie A club's chief executive, Adriano Galliani, said on Tuesday.
Exhausted Inter Milan risked surrendering their long-held Serie A lead after drawing 1-1 at fourth-placed Palermo on Saturday.
Kaka's move to Manchester City fell through because AC Milan '"bottled it', City's executive chairman Garry Cook said on Tuesday. Cook was part of a group of City officials who spent seven hours in the Italian city on Monday trying to secure the world record transfer of the Brazilian midfielder, only for the Italian club to announce that no deal would take place.
Gennaro Gattuso finally had fans talking about his talent rather than his temper after his rare goal gave AC Milan a 1-0 win at beleaguered Juventus and stretched their Serie A lead to eight points on Saturday.
Serie A leaders Inter Milan ground out a 1-0 victory at Chievo and Juventus ended their bad run with a similarly battling 2-1 win at Parma on Wednesday.
AC Milan are still interested in Manchester City forward Carlos Tevez but only want to sign players on loan in the January transfer window, chief executive Adriano Galliani said on Monday.
Competition favourites AC Milan will face Werder Bremen, one of the Champions League dropouts, in the last 32 of the UEFA Cup following Friday's draw in Nyon, Switzerland.
Andrea Pirlo will spend the rest of his career at AC Milan and will not join former boss Carlo Ancelotti at Chelsea, the Serie A club's owner Silvio Berlusconi said on Wednesday.
Champions League competitors Schalke 04 have signed AC Milan midfielder Kevin-Prince Boateng on a four-year deal after the Ghana international passed his medical at the German club on Friday.
Real Madrid have signed Brazilian midfielder Kaka from AC Milan, the Primera Liga club said on their website (www.realmadrid.com) on Tuesday.
Real Madrid have signed Brazilian midfielder Kaka from AC Milan, the Primera Liga club said on their website (www.realmadrid.com) on Tuesday.
AC Milan have agreed to sign Ghanaian forward Dominic Adiyiah from Norway's Fredrikstad in January while a loan deal for David Beckham will be announced soon, chief executive Adriano Galliani said on Saturday.
Juventus bounded to the top of Serie A by securing a battling 2-0 victory at Palermo after former striker Amauri condemned AC Milan to a 2-1 defeat at home to Fiorentina on Saturday.
Alexandre Pato fired home in injury time to give AC Milan a lucky 2-1 win at Fiorentina on Wednesday to send the Rossoneri up to second in Serie A.
Images from the UEFA Champions League matches played on Tuesday night.
