"We were unlucky not to go in at half-time ahead," admitted the Reds boss.
"Barcelona are so good going forward, they play such nice football, but we stuck in there and are in the last eight now.
"We've got great spirit, grit and determination - people were throwing bodies about and that's one of the reasons we're through.
"It gives us great confidence, going through against the best side in Europe over two legs."