Barcelona scored - Anthony Elanga responded.
The Swedish international scored two goals in the first half of the Champions League second leg in Spain, ensuring Newcastle kept pace with the La Liga giants.
But it wasn't enough for the Premier League club in the end.
At the end of the first half, star Lamine Yamal made it 3-2 on a late penalty - and in the second half the home team put on a show.
A 4-2 in the 51st minute by Fermín López was followed by 5-2 and 6-2 by Robert Lewandowski in the 56th and 61st minutes respectively. Raphinha scored his second goal when he made it 7-2 with just over a quarter of an hour left in the regular 90 minutes.
Barcelona thus continues to chase the trophy that will be awarded in Budapest in May, while Newcastle can close the Champions League chapter for this season.
Anthony Elanga, named in Sweden's national team squad for the World Cup play-offs later in March, played 64 minutes. Barcelona's Roony Bardghji - also named in national team captain Graham Potter's Swedish squad - remained on the bench.
