After Luis Suarez, Lionel Messi and Neymar had starred for the Catalans as they relegated their hosts with a rampant result, the European champions needed a hat-trick from Cristiano Ronaldo to see off Unai Emery's 10 men.
"Barcelona are a brilliant team," the Italian responded when asked about Barca staying two points clear in the Spanish title race. "Their attackers are very effective. They are all so good. It's no surprise they can score so many goals."
Ancelotti also gave his thoughts on his side's victory over the fifth-placed side at the Ramon Sanchez Pizjuan, which not only extended their unbeaten streak to nine games since their Clasico defeat at Camp Nou in March but also set them up nicely for next week's Champions League trip to Turin.
"It was not easy to win here, and we are pleased to have achieved that victory," the former AC Milan coach told reporters.
"It's a very important win. It means La Liga is still winnable and it gives us confidence for Tuesday's semi-final first leg against Juventus.
"Now is not the time to look back at games when we lost points, at the end of the season we will analyse.
"We have lost points, especially when we have been without the likes of Karim Benzema, Luka Modric, James Rodriguez and Sergio Ramos due to injury."
In addition to two Champions League semi-finals against Massimiliano Allegri's Italian champions, Real Madrid have Liga games against Valencia, Espanyol and Getafe to look forward to this month.
