Napoli's decision to loan Emanuele Calaio to Genoa came back to haunt them on Monday when the 32-year-old scored with a late free kick in a 1-1 Serie A draw costing his owners two points in the race for a Champions League spot.
Carlos Tevez scored a stunning goal as Serie A leaders Juventus beat Torino 1-0 on Sunday to continue an extraordinary dominance of their neighbours.
Portuguese forward Cristiano Ronaldo needed to take time off and even miss games if he is to see out an arduous season after he limped off before the end of Real Madrid's 3-0 victory over Villarreal on Wednesday, according to manager Zinedine Zidane.
Marcelo Zalayeta capitalised on an early blunder by Inter Milan keeper Julio Csar as Napoli ended the leaders's unbeaten record in Serie A on Sunday with a 1-0 home win.
Roma came from behind to beat Real Madrid while Chelsea were held in Tuesday night's Champions League matches.
Barcelona's last Champions League triumph came in 2015, and since then they have failed to get beyond the quarter-finals while Real Madrid have monopolised the trophy.
Barcelona put one foot in the Champions League last 16 with a 5-0 away drubbing of Basel and are the only team with a 100 percent record.
Second-placed Napoli comfortably overcame the absence of suspended top scorer Gonzalo Higuain to brush aside bottom-of-the-table Verona 3-0 in Serie A on Sunday. Napoli stayed points six behind leaders Juventus, who won 2-1 at AC Milan on Saturday, with six matches each to play, and remain outsiders to win their first title since 1990 despite the win. Higuain, who has led Napoli's challenge with 30 goals, will miss the next three games as he completes a four-match ban for his sending-off and furious reaction in last week's 3-1 defeat at Udinese. Fiorentina's recent dismal run continued when they lost to their smaller Tuscan neighbours Empoli for the first time since 1997, leaving them fifth in the table. Juventus have 76 points from 32 games with Napoli on 70, AS Roma on 63, Inter Milan on 58 and Fiorentina on 56. Napoli hit the post twice and had a goal disallowed before Manolo Gabbiandini headed them in front in the 33rd minute, his fifth goal in only seven starts this season, after Verona goalkeeper Pierluigi Gollini parried Jose Callejon's shot.
Jose Mourinho said on Sunday that he intends to return to the Premier League when his time as Inter Milan coach comes to an end.
News of all that's transpired on and off the football field
AC Milan went out of the Italian Cup after being held 1-1 at Catania, while AS Roma crushed Torino 4-0 to reach the quarter-finals.
News of all that's transpired on and off the football field
Check out the top footballers of the weekend...
Three time European champions Inter Milan were stunned 2-0 at home by Israeli side Hapoel Beer-Sheva and Manchester United were floored by a late goal from Feyenoord as the Europa League group stage got underway on Thursday.
Cristiano Ronaldo opened the scoring as Juventus beat visiting Bologna 2-1 on Saturday to move four points clear at the top of the Serie A table. Ronaldo struck from close range after 19 minutes, but Danilo levelled for the visitors soon afterwards.
Cristiano Ronaldo was booed by Real Madrid fans despite grabbing one goal and laying on another in their 2-0 Champions League last-16 second leg win over AS Roma on Tuesday.
AC Milan striker Marco Borriello has been suspended after testing positive in a routine doping test.
Two supporters were kept in overnight and a local hospital spokesman said one fan had suffered stomach wounds as 10-man United lost their quarter-final, first leg 2-1.
Manchester United and Chelsea will both be putting their quests for domestic dominance to one side on Wednesday and turning their attentions instead to European glory.
Struggling Rayo win at Valladolid after late penalty save
Chelsea also got their Champions League campaign off to a good start, beating Werder Bremen 2-0.
Images from the Champions League matches played on Wednesday
News of all that's transpired on and off the football field
News of all that's transpired on and off the football field
News of all that's transpired on and off the football field.
Zlatan Ibrahimovic scored a dubious penalty as 10-man Inter Milan beat second-from-bottom Empoli 1-0 on Sunday to pull eight points clear at the top of Serie A.
The Premier League leaders will be without Rio Ferdinand, Gary Neville, Nemanja Vidic and Mikael Silvestre for their Champions League semi-final against Inter Milan.
News of all that's transpired on and off the football field
AS Roma captain Francesco Totti has warned Manchester United coach Alex Ferguson not to underestimate him when their two sides play the first leg of their Champions League quarter-final next week.
Captain Paul Pogba produced an outstanding performance garnished by two goals to help Manchester United to a resounding 3-0 win at Swiss debutants Young Boys Bern in their Champions League Group H opener on Wednesday.
Barcelona went out of the Champions League in the first knockout phase on the away goals rule despite a 1-0 win over Liverpool.
Inter Milan notched up their 17th successive Serie A victory with a 5-2 win at Catania on Sunday.
A round-up of Wednesday's Champions League first knockout round, first leg ties.
Everyone at Manchester City is flying high after the 1-0 derby win over Manchester United at the weekend but they could all come crashing back to earth after Wednesday's meeting with CSKA Moscow in the Champions League.
champions Inter Milan are now three points clear at the top of Serie A with 17 points from seven games courtesy of their 2-1 win over Napoli.
Inter Milan extended their lead at the top of Serie A to four points when Patrick Vieira scored the winner in a 2-1 victory at Palermo.
Juventus coach Massimiliano Allegri has confirmed that the Serie A leaders are interesting in signing Dutch midfielder Wesley Sneijder from Galatasaray.
'So, the Champions League final will be played between two teams who just don't know when they are beaten,' says Suhit K Sen.
Major world record deals are here.
Lopetegui blends youth and experience in Spain World Cup squad