Fresh from scoring a hat-trick in his side's 3-0 triumph over Sporting last week, Tello again proved decisive at Estadio Municipal de Braga.
The on-loan Barcelona forward latched on to a through ball from substitute Vincent Aboubakar and coolly clipped the ball over Matheus Nascimento with 17 minutes remaining.
Fourth-placed Braga were unable to respond as their six-match winning run in all competitions came to an end.
Porto have now triumphed in six league matches on the spin themselves and trail Benfica by a point ahead of the latter's trip to lowly Arouca on Sunday.
Get the best features, fun and footballing frolics straight to your inbox every week.
Thank you for signing up to Four Four Two. You will receive a verification email shortly.
There was a problem. Please refresh the page and try again.