Scott Kashket notched his 15th goal of the season as Wycombe leap-frogged visitors Portsmouth to sixth in the League Two table with an edgy 1-0 win.
Kashket's deflected shot early in the second half was enough to settle the match at Adams Park despite a tense end to the game.
Jamal Lowe, making his first start for Pompey since his January move from Hampton & Richmond, came just inches away from opening his account with a smart left-footed strike just wide of the right-hand post.
But that was the best it would get for Pompey, who suffered a frustrating afternoon at the hands of a well-drilled and professional Wycombe outfit.
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Kashket netted the decisive goal with just three minutes played of the second half, though he needed a generous deflection to wrong-foot keeper David Forde, who could only watch helplessly as the ball trickled past him and into the bottom corner.
Despite an astonishing nine minutes of stoppage time played by referee Graham Salisbury, it was not enough for Pompey, who failed to create any notable openings for an equaliser as Wycombe ground out victory.