Goals from Dani Olmo, Raphinha, and an acrobatic Lamine Yamal strike powered the Catalans to 52 points, one ahead of Real Madrid.
IMAGES from UEFA Champions League matches played on Wednesday
A round-up of Tuesday's action in the UEFA Champions League.
Liverpool shrugged off the absence of Mohamed Salah as midfielder Dominik Szoboszlai scored an 88th-minute penalty to give them a 1-0 Champions League win at Inter Milan.
Virgil van Dijk scored with a stunning late header in the second minute of stoppage time to give Liverpool a 3-2 victory over Atletico Madrid in their opening group stage match of the Champions League, at Anfield, on Wednesday.
IMAGES from the UEFA Champions League matches played on Wednesday
Manchester City's Erling Haaland came back to haunt Borussia Dortmund with a clinical finish against his former team, while Phil Foden bagged a brilliant brace as the hosts cruised to a 4-1 win in the Champions League on Wednesday to climb to fourth.
IMAGES from the Europa League matches played on Thursday
Manchester City spent more than 180 million pounds ($223.58 million) -- more than the combined amount paid by the other 19 English top-flight clubs in a relatively quiet window.
Manchester City's spending of more than 180 million pounds ($223.58 million) was the second-biggest outlay ever worldwide by a club in the January transfer window.
Liverpool hammered Sparta Prague 6-1 on Thursday to storm into the Europa League quarter-finals 11-2 on aggregate.
Liverpool draw Sparta Prague in Europa League last 16
IMAGES from the Europa League matches played on Thursday
Forward Rasmus Hojlund scored twice to allow Manchester United to come back from a goal down and get a 2-1 win at six-times Czech champions Viktoria Plzen in the Europa League on Thursday.
The win leaves United in 15th place in the Europa League standings on six points from four games.
An early penalty by Alexis Mac Allister and a Darwin Nunez brace helped Liverpool to thrash Sparta Prague 5-1.
Jose Mourinho's side top Group G with a maximum nine points, three clear of second-placed Slavia.
IMAGES from the Europa League matches played on Thursday.
Liverpool will take on LASK, Union Saint-Gilloise and Toulouse in the Europa League group stage while debutants Brighton & Hove Albion will face Ajax Amsterdam and Olympique de Marseille following the draw on Friday.
Dani Olmo came off the bench in the second half to give Barcelona the spark they needed on his debut, against Rayo Vallecano.
Rennes denied late Europa League equaliser due to little-known rule
Brighton secured their second victory of the competition with a comfortable win at Ajax thanks to goals from Ansu Fati and Simon Adingra.
Former Bayern Munich coach Flick takes over Germany to 2024
Runaway Premier League leaders Manchester City will play Borussia Dortmund with the winners to face either Bayern or PSG in the semi-finals.
Liverpool received a relatively kind draw for the group stage of this year's Champions League
IMAGRS from the soccer matches played across European leagues on Friday
Chelsea will face Dynamo Kiev at home in the first leg of their Europa League last-16 tie, while London rivals Arsenal will travel to Rennes following Friday's draw in Nyon, Switzerland.
IMAGES from Europa League matches played on Thursday.
IMAGES from Europa League matches played on Thursday.
In the third-tier Europa Conference League, English Premier League club Leicester City will face Danish side Randers and Scottish club Celtic will take on Norwegian champions Bodo/Glimt in the knockout playoff round.
The three Premier League and three La Liga clubs in the last eight avoided each other, with Manchester City up against Atletico Madrid and Liverpool to face Portuguese side Benfica.
Seven-time European champions AC Milan hit back from two goals down against Celtic to claim a 4-2 victory that sent them into the Europa League knockout phase on Thursday as they were among 14 teams to progress in Europe's second-tier competition.
Sixteen-year-old Romelo Lukaku scored twice in nine minutes to give Anderlecht a 3-1 victory at Ajax Amsterdam on Thursday, sending the Belgians into the knockout stages of the Europa League.
AC Milan have been drawn to play Manchester United in what is the standout tie in next month's Europa League round of 16.
Hamburg led a trio of former European champions into the UEFA Cup knockout phase on Thursday and previous winners Valencia also secured a last 32 place. Aston Villa and Ajax Amsterdam progressed from Group F along with Hamburg, whose 2-0 victory at Slavia Prague meant Villa qualified despite a 2-1 home defeat by Slovakia's Zilina.
Arsenal are on a roll having won their last 12 matches in all competitions, while Liverpool smarting from a defeat in the Champions League.
A round-up of the weekend soccer action in eastern Europe.
Manchester United routed Dynamo Kiev 4-0 while a goalless draw saw Arsenal through to the Champions League knockout stages.
Arsenal and Manchester United will be looking to make it four wins out of four in the Champions League this week after playing out an enthralling 2-2 draw in the Premier League on Saturday.
Arsenal demolished Slavia Prague 7-0 in Champions League Group H on Wednesday with one of the most brilliant displays of attacking football since the Champions League began 15 years ago.