Sunderland missed the chance to go top of League One on a frustrating afternoon at the Stadium of Light.
Substitute Josh Maja scored his eleventh goal of the season but Wycombe Wanderers battled hard and continued their impressive recent form.
Sunderland responded well to going behind early in the second half and ultimately remain unbeaten in 12 games.
Their eight game winning sequence came to an end, however, leaving Portsmouth two points clear at the top of the League One table.
The Black Cats laboured through a poor first half in which they created the best chance but found themselves largely second best.
Their start was promising, Aiden McGeady released by Chris Maguire and firing over the bar from just inside the box.
That opening raised hopes for an expansive display but Wycombe Wanderers quickly made an impression with their organisation and intelligent pressing game.
They sat deep and waited for Sunderland to play the ball into the midfield areas, where they quickly sprang out in packs, often winning it back an dbreaking up field.
On the half hour mark they missed a glorious opportunity to take the lead, Adam El-Abd heading wide when free for a corner.
Soon after Jerome Sinclair lost the ball on the edge of the Wycombe box, the visitors breaking clear. Fred Onyedinma did well to make the byline, his shot deflected into the side netting.
The Black Cats were struggling, though they forged a massive chance when Sinclair flicked a long ball into the path of McGeady, the winger firing wide with the goal gaping.
Their start to the second half was good, Jack Baldwin again releasing McGeady with a superb early ball into the channel. The Irishman crossed and Sinclair was inches away from making the crucial connection.
Sunderland forced a succession of corners but Jack Ross moved quickly to change it, replacing Dylan McGeouch and Jerome Sinclair with Max Power and Josh Maja.
The two quickly combined when Power found Maja with a long pass. The youngster found a yard of space but his shot was deflected wide.
Sunderland's tempo was much better but with just over 20 minutes to go, a lapse in concentration saw them fall behind.
The Black Cats didn't deal with a ball into the box and when it broke free, Onyedinma was on hand to fire into the roof of the net.
Subsitute Josh Maja went close on the half-volley soon after and with ten minutes to go, he set up a grandstand finish.
George Honeyman picked the ball up out wide and showed an excellent turn of pace to beat his marker. He crossed for Maja who took a touch before firing home with trademark composure.
The Black Cats pushed for a winner and came close when Matt Ingram had to turn a powerful drive from Power wide of the post.
It looked as if the midfielder would seal a stunning winner when he met a cross from McGeady at the back post in stoppage time, but Wycombe were able to make the vital block and secure a point.
Sunderland XI:McLaughlin; Matthews, Flanagan, Baldwin, James (Oviedo, 75); McGeouch (Power, 54), Honeyman; Gooch, Maguire, McGeady; Sinclair (Maja, 54)
Subs: Ruiter, Loovens, Ozturk, O'Nien
Wycombe Wanderers XI: Ingram; McCarthy, El-Abd, Jombati, Jacobson; Gape, Thompson; Onyedima (Cowan-Hall, 90), Morris, Williams (Tyson, 72); Samuel (Mackail-Smith, 82)
Subs: Yates, Bean, Stewart, Kashket
Bookings: Honeyman, 23 Gabe, 71