Tenconi levelled in the first half after bravely heading into the back of the net after Freddie Grant dug out a fantastic cross from the left-hand side.
This came after the hosts started strongly and deservedly took the lead on 13 minutes.
Lewis Coyle played a precision pass in behind the defence, finding Joe Iaciofano making a run towards goal, smashing the ball into the right-hand side of the net.
On the half hour mark, the combination of Worsfold and Tenconi nearly gave Slough the lead after growing into the match.
Tenconi held off challenges and laid the ball pack to Worsfold, who wrapped his right foot around the ball with a curling strike hitting the inside of the post.
Just before the break, City restored their advantage thanks to an outrageous strike from Oxford skipper Elliot Benyon.
Rebels stopper Michael Edegbe swept up at the back but didn’t clear his lines fully. Benyon eyed up the goal, and with precision drove the ball into the top of the net as Edegbe desperately scurried back to his goal.
On 71 minutes, the hosts doubled their advantage after Iaciofano slipped in the overlapping George Harman down the left-hand side, who confidently drilled the ball under Edegbe.
Slough responded swiftly, with Tenconi netting his second of the game.
Scott Davies floated a hanging ball from midway inside the Oxford half with the keeper Ben Dudzinski misjudging the flight, leaving Tenconi with the simplest of headers into an empty net, giving them a glimmer of hope.
As the game entered the latter stages, Tenconi almost capped an outstanding display with a hat-trick.
A nod down inside the box from substitute Ben Harris found Tenconi, whose snapshot at goal was denied by the advancing Dudzinski, who spread his body well to prevent a late leveller.
Almost immediately after, Rebels debutant Tyler Goodrham was denied by the woodwork from a tight angle on the right-hand side after being found by a cross down the left.
Oxford tested the Slough backline throughout the contest, with close range efforts from Coyle and Iaciofano forcing smart saves from Edegbe.
Slough will be disappointed not to get anything from the match after a spirited display on the road, but they have a chance to bounce back at home to Hampton and Richmond Borough on Tuesday afternoon.
Oxford City Line up
Ben Dudzinski, Zico Asare, George Harmon, Josh Ashby, Lewis Coyle (Alfie Potter 89), Elliot Benyon (c), Zac McEachran, Nana Owusu, Joe Iaciofano, Jack Davies, Canice Carroll. Unused substitutes: Jacob Bancroft, Alex Grantham, Ewan Clark, Harry Kyprianou.