Lionel Messi, Luis Suarez, Neymar and Xavi all had at least one goal and one assist in the match.
That is such a rare occurrence that Spanish football statistician MisterChip confirmed it had never been done before this century.
For the first time in this century, 4 players (Messi, Neymar, Suarez and Xavi) have scored and assisted in a La Liga match
— MisterChip (English) (@MisterChiping) April 28, 2015
What made the achievement even more impressive was the fact that it was completed by half-time with Barcelona leading 5-0 at the break.