The Millwall loanee pounced early in the second half after visiting keeper Bobby Olejnik had kept the Blues at bay before the interval with a succession of outstanding saves.
New signing Marcus Bean came straight into the side with Sam Wood moving into an advanced position in the absence of injured captain Paul Hayes, so Peter Murphy took the armband in a midfield three.
Fred Onyedinma hit an early shot wide as he looked to build on his first professional goal the previous week against Hartlepool, and he had an even better chance on five minutes when the ball fell kindly for him only to see York’s debutant keeper Bobby Olejnik make himself big and block his shot, before Aaron Pierre headed a cross over.
Then it was Marcus Bean who almost broke the deadlock, latching onto a ball inside the area after good play from Onyedinma, but Olejnik again spread himself to maintain the deadlock.
Peter Murphy was the next to see a sight of goal but Marvin McCoy denied him with a fine block before the ball fell to Wood, whose well-hit shot from 25 yards flew narrowly over.
Olejnik refused to be beaten and made a stunning reaction save to parry away Pierre’s fierce header from Joe Jacobson’s delivery, before the game began to settle with City learning how to stifle the hosts’ bright attacking play.
Keith Lowe then hooked over the bar for the Minstermen when a corner reached him at the back post, before Alfie Mawson unleashed a dangerous low swerving effort from distance which Olejnik did well to get fully behind.
But Olejnik was determined to impress on his debut and made yet another fine intervention when a cross into the six-yard box was turned goalwards by Onyedinma only for the keeper to thrust out a leg to meet the ball.
York improved midway through the half and almost had an equaliser when Marvin McCoy’s deflected effort from distance looked destined for the top corner before Matt Ingram produced a wonderful one-handed save to preserve his side’s lead.
The visitors were putting up a good fight and caused some nervy moments, with strikers Wes Fletcher and Jake Hyde causing a nuisance with their movement and impressive hold-up play.
Onyedinma tried to secure the points firstly by cutting in and shooting straight at Olejnik, and then firing wide in stoppage time under pressure from the defender.
But the one goal was enough as Wycombe reached 50 points - the same tally they reached in total last season, with 21 games still to play.
Wycombe: Ingram, Jombati, Jacobson, Mawson, Pierre, Bean, Murphy, Scowen, Wood, Holloway (Craig 84), Onyedinma (McClure 90).
Unused subs: Richardson, Rowe, Fletcher, Bloomfield, Senior.
York: Olejnik, McCoy, Ilesanmi, Lowe, McCombe, Carson (Meikle 68), Penn (Morris 80), Summerfield, Coulson, Hyde, Fletcher.
Unused subs: Mooney, Straker, Winfield, Montrose, Platt.
Ref: Mr O Langford
Attendance: 3,669 (324 from York)
Winning 50/50 Draw Number: 130787
Prize Money: £715.50