An early Cole Palmer goal was cancelled out by Georginio Rutter and Kaoru Mitoma of the Seagulls to help them advance into the next round.
After suffering a 7-0 defeat at the hands of Nottingham Forest last weekend, Chelsea seemed like a big test for Brighton, but Fabian Hurzeler's men did an exceptional job to turn things around and take the win on the night against Enzo Maresca's side.
The Blues had a lucky start to the game as Cole Palmer's volley in the fourth minute was completely fumbled by Bart Verbruggen - who completely misjudged it, leading it to cross the line
However, the Seagulls were relentless in their approach after conceding and did not take too long to equalise through Gerogino Rutter, who headed home the cross by Joel Veltman in the 12th minute.