Brighton and Hove Albion beat Chelsea in the FA Cup after playing them in the competition for the first time since 1973.
The first goal came from a huge error from goalkeeper Bart Verbruggen who parried a Cole Palmer shot into his own net.
Albion fought back with a well-headed goal from Georginio Rutter.
The Seagulls took the lead in the second half with Kaoru Mitoma scoring the winner just as he did at the same stage against Liverpool two years ago.
Verbruggen made up for his error with a couple of good saves including one in the final minutes of the match.
Three former Seagulls playing for the Blues – Marc Cucurella, captain Moises Caicedo and goalkeeper Robert Sanchez – were repeatedly roundly booed by Albion fans.
With the score at 1-1 Christopher Nkunku latched on to a cross when well placed but, instead of taking his chance, squared to Cole Palmer whose header landed on the top netting.
And Georginio, clear of his marker Cucurella, flashed a ball across Chelsea’s six-yard box, clear of Sanchez, but no Albion player could capitalise.
The first half was punctuated by an injury to Lewis Dunk. He received treatment several times and was replaced by Adam Webster at the start of the second half.
Pedro Neto had a great chance to put Chelsea back in front early in the second half but this was blocked by Kack Hinshelwood.
Albion looked more fluid with Webster at the back and, when Georginio found Mitoma in the box, the Japan international lifted the ball over his former team-mate Sanchez with a delightful chip. Cucurella chased the ball home and ended floundering in the back of the net.
Chelsea’s only real clear chance to equalise fell to Noni Madueke right at the end but, after a marauding run, his shot was blocked when several Chelsea players were better placed.
Albion are number 3 in the 5th round draw on Monday (10 February) and, for good measure, host Chelsea again at the Amex for a Premier League match on Friday (14 February) – Valentine’s Day. Gotta love that!