The Londoners had pegged their opponents back after Porto took an early lead, but Mario Silva’s team pulled away in the second half.
Porto missed a gilt-edged chance to take the lead early on when Fabio Silva scuffed his shot after rounding the Chelsea goalkeeper Karlo Ziger to leave himself with an open goal. Marc Guehi cleared the shot off the line.
The Portuguese club took the lead soon after when Fabio Vieira swept home at the back post after excellent work by Mor Ndiaye on the right wing in the 17th minute.
Chelsea came close when Billy Gilmour hit a rasping drive after half an hour, but his shot was comfortable for Diogo Costa in the Porto goal.
Porto’s Joao Mario almost doubled his side's lead with a shot ten minutes before half-time, but his left-footed effort went agonisingly wide.
Luke McCormick had a good chance to pull his side level as half-time approached, but saw his shot blocked by Costa as he moved smartly off his line.
After 53 minutes, Deishawn Redan nodded home from a Juan Familio-Costa cross to restore parity for the Blues.
Porto saw a Diogo Leite header saved at point-blank range by Ziger but retook the lead immediately through a fortunate Diogo Quieros goal just a minute after Redan’s equaliser. The Porto captain deflected home after
Conor Gallagher had a good chance to bring things back level midway through the second
With 20 minutes of the game
Porto scored a third going into the game’s final fifteen minutes. Ziger was only able to divert Alfonso Sousa’s shot onto the post and into the net after Sousa was set up by a cute backheel from Romario Baro.
Chelsea responded by sending on Charlie Brown, who had scored 12 goals in the competition, alongside Faustino Anjorin, but it was to no avail, as Porto saw the game out to win the trophy.