The 21-year-old Hackney’s silky finish from an Isaiah Jones pass stunned the visitors in the 37th minute at the Riverside Stadium and the hosts defended superbly to take a slender advantage to Stamford Bridge.

Chelsea only had themselves to blame though as they dominated possession but squandered a host of chances — the biggest culprit being Cole Palmer who failed to hit the target twice in the opening half with the goal gaping.

Boro, who won the trophy in 2004, had chances on the counter-attack to increase their lead but will head to London believing they can reach Wembley.

Chelsea’s players were booed by some of their own fans at the final whistle but will have the chance to make amends in the second leg on Jan 23.

Liverpool host Fulham in the first leg of the other semifinal on Wednesday.