OXFORD City were unable to build upon a recent upturn in form when they fell to a 1-0 defeat at Dartford in Vanarama National League South.
Coming up against a side unbeaten at home and on an eight-match winning streak in all competitions, City matched their hosts throughout.
But they were undone by one momentary lapse two minutes before the break, with Andy Pugh scoring what turned out to be the winner.
City started brightly, with Jonny Giles and Jefferson Louis both firing just wide in the opening five minutes.
But at the other end they remained vulnerable and were indebted to some fine goalkeeping from Stevens.
The Oxford United loanee denied the unmarked Pugh at point-blank range after he was left unmarked at the back post 23 minutes in.
They were caught out again shortly after when Elliot Bradbrook beat the offside trap, only for Robbie Cundy to recover brilliantly and rob him of the ball as he was about to pull the trigger.
But when City were finally breached just two minutes before the break, it was frustratingly simple after they failed to deal with a direct aerial attack.
Bradbrook nodded on a long goal kick for Pugh to flick over the head of the stranded Stevens.
Ryan Hayes could have doubled their tally in first-half stoppage time with a dangerous cross-shot which threatened to sneak beneath the bar before being palmed over by a back-pedalling Stevens.
The City keeper was kept busy early in the second half as well, pushing away Duane Ofori-Acheampong’s low strike three minutes after the restart.
City began to build some pressure at the other end as they sought an equaliser, but failed to create enough clear-cut openings.
Tom Winters’s 68th-minute free-kick was straight at the goalkeeper, while five minutes later an excellent incisive passing move ended with Reece Fleet drilling a shot wide of the target.
But City’s efforts to go forward left them vulnerable to the counter-attack and the hosts twice had the ball in the back of the net in the closing stages, only to be denied by the offside flag.
Ellis Brown prodded home one close-range effort and Pugh slipped a second past Stevens in stoppage time, but both times their celebrations were cut short.
That mattered little in the end though, as City were unable to prevent their brief two-match unbeaten run coming to a halt.
Oxford City: Stevens, Poku, Grant (Ngathe 86), Ashby, Henderson, Cundy, Fleet, Giles, Louis, Roberts (Fondop 63), Winters (Ofosu 79). Sub not used: MacAuley.