Wanderers' unbeaten away record came to an end in a dramatic encounter at the Lamex Stadium.After an even start, Boro keeper Jesse Joronen stunned the game into life with a goal from just outside his own box which sailed over the head of Matt Ingram and into the net after one bounce.
Wycombe found themselves two down when Armand Gnanduillet headed home from a corner but three substitutions breathed new life into the visitors and they halved the deficit through Max Kretzschmar.
However they couldn't force an equaliser and will look to bounce back with successive home games at Adams Park this week, starting with the visit of Newport County on Tuesday.
Gareth Ainsworth made three changes to the side which started the Blues’ last league game a fortnight ago, with Jason McCarthy being handed a debut at centre-back while Matt Bloomfield and Max Kretzschmar came into the midfield.
Wanderers started well and saw Joe Jacobson’s inswinging corner almost drop beneath the crossbar before keeper Jesse Joronen tipped it away, and Marcus Bean’s shot was then blocked en route to the corner of the net.
But Joronen was involved in a major way in the game’s opening goal – incredibly, he was the scorer, and it came from a long punt downfield which Matt Ingram misjudged and saw it bounce over his head and into the net.
It sent the Lamex Stadium into a state of shock but the Wanderers fans reacted immediately by singing in support of their goalkeeper, and their team were almost level when another corner by Jacobson struck Pierre at the back post and bounced narrowly wide.
The visitors gradually cranked up the pressure with Marcus Bean pulling the strings in the middle and the front five interchanging smartly, leading to a terrific move which ended when Steven Schumacher brought down Max Kretzschmar just outside the box, and Jacobson’s free-kick was blocked.
Neither side really threatened to add to the score before the break although Armand Gnanduillet came close with a header which bounced off the top of the bar from Jerome Okimo’s cross.
Wycombe had an unbeaten away record to salvage but they almost had a greater mountain to climb when Dean Parrett met Armand Gnanduillet’s knockdown and sent a header towards the bottom corner which seemed destined to hit the net before the timely intervention of Ingram to toe it clear.
Then it was Steven Schumacher’s turn to produce the heroics when Garry Thompson whipped in a superb cross which Max Kretzschmar stooped to meet, only for the Boro midfielder to slide in and hack it clear in the nick of time.
But heroic defending was nowhere to be seen when Stevenage doubled their lead through Armand Gnanduillet who lost his marker to head home the simplest of goals from a corner from a left, barely four yards from the line.
Wycombe reacted by making a double change, bringing on Aaron Amadi-Holloway and Michael Harriman, but by now Stevenage had grown in confidence and didn’t look like letting their lead slip.
Joronen blocked a scrambled Jason McCarthy effort inside the six-yard box and hope arrived with 10 minutes remaining when the impressive Harriman delivered an impeccable cross which Max Kretzschmar powered home with an unmarked header, lifting the spirits of those fans behind the goal.
Then Ryan Sellers headed straight at the keeper from another Harriman cross, and in stoppage time, Sellers’ deep cross was met by McCarthy who couldn’t keep his header down.
Matt Ingram denied Gnanduillet at the other end when the striker broke through, but there was no to be no late drama as Wanderers lost away on a Saturday for the first time in 18 months.
Wycombe: Ingram, Jombati, Jacobson, McCarthy, Pierre, Bean (Sellers 76), Bloomfield (Harriman 65), O’Nien, Kretzschmar, Ugwu (Amadi-Holloway 65), Thompson.
Unused subs: Lynch, Rowe, McGinn.
Stevenage: Joronen, Franks, Okimo, Hughes, McCombe, Schumacher, Parrett, Whelpdale (Pett 23), Conlon, Kennedy (Williams 65), Gnanduillet.
Unused subs: Day, Kerr, Smyth, Jebb, Loza.