Gerard Lopez's side now look hot favourites to clinch promotion with the second leg set to take place on Sunday 25 June.
However, ahead of that, feel free to sit back, relax and watch all the goals from Sunday's superb victory.
Despite going behind, Barca B roared back to win the game with Marc Cardona and Dani Romero both scoring twice and goalkeeper Jose Suarez also saving a penalty.
[HIGHLIGHTS] FUTBOL (2AB): Racing - FC Barcelona B (1-4)
The goals of Barça B's brilliant victory vs Real Racing Club (1-4) Els gols del brillant triomf del Barça B a El Sardinero (1-4) Los goles del brillante triunfo del Barça B contra el Racing (1-4) https://www.youtube.com/watch?v=tfVfatDAZ1Y #FCBMasia #ForçaBarçaPosted by FCB Masia on Monday, June 19, 2017