The match was played at the Amex Stadium in Brighton as Graham Potter led his side against his old club just over a week after leaving in a £20million compensation deal.
Both sides played a mix of senior and youth players as they coped with the cancellation of their Premier League fixtures due to a lack of policing after the Queen’s passing last week.
Those players who faced RB Salzburg in midweek and are due to join up with their national team squads were allowed time off for the semi-competitive training match.
It meant runouts for the likes of Christian Pulisic, Ruben Loftus-Cheek, Trevoh Chalobah, Armando Broja, Denis Zakaria and Conor Gallagher.
Chukwuemeka, who has yet to make his first-team debut since joining in a £20m deal from Aston Villa, proved the match winner in the 2-1 victory as he took his chances in front of Potter.
Chelsea do not play until October 2 when they face Crystal Palace at Selhurst Park.
They were due to face Liverpool this weekend and the postponed match is yet to be rescheduled.
Similarly, Brighton were due to face Palace in the Premier League, a game originally called off due to a now-delayed train workers strike that was also not spared ahead of Monday’s funeral in London.