Sam Vokes’ first-half strike condemned the Addicks to a first home league defeat under Johnnie Jackson at The Valley on New Year’s Day.
The Charlton manager made three changes from the 1-0 reverse at Plymouth Argyle a fortnight ago, restoring Akin Famewo, Conor Washington and Josh Davison to his starting XI as Jayden Stockley missed out owing to a minor niggle.
The visitors administered the first opening of the afternoon as Vokes flicked on for strike partner Brandon Hanlan, but Craig MacGillivray was out promptly to snatch the ball from the former Addick’s feet.
Minutes later Charlton countered through Alex Gilbey, who threaded a neat ball through to Washington as the Northern Ireland international burst into the box, only for Christian Forino-Joseph made a vital interception.
Wycombe took the lead on 35 minutes, though. Having received the ball from Jason McCarthy down the right flank, Garath McCleary surged past George Dobson before delivering a low centre for the obliging Vokes to smash into the roof of the net from a matter of yards.
Only a flying save from David Stockdale prevented Lee from restoring parity four minutes before the interval, the Wycombe stopper diving well to his left to turn away the Luton Town loanee’s curling effort after intricate build-up play between the latter and Dobson.
Jonathan Leko replaced Davison after the restart as Jackson shuffled his pack, although it was the visitors who crafted an immediate flurry of chances.
First, Hanlan outmuscled Jason Pearce to latch onto Joe Jacobson’s header forward and curl into the grateful grasp of MacGillivray, before McCleary saw a low drive from distance deflect wide of the Scotsman’s right upright.
The Addicks went agonisingly close to levelling proceedings moments before the hour mark when Gilbey reached the byline to pull back for Leko, only for the ball to seemingly strike the substitute’s heel and bounce back off the woodwork.
Leko was involved again soon after, this time driving into the box from the left to force Stockdale into another smart stop, before Jack Grimmer produced a goal-saving tackle to deny the Birmingham City loanee again just four minutes later.
Washington was next to threaten Stockdale, drilling a low effort narrowly wide of the keeper's right upright from the edge of the 18-yard box.
Ryan Inniss entered the fray with a matter of minutes remaining as Jackson upped the ante once more, with the towering defender operating up front alongside fellow substitute Mason Burstow and Washington in the latter stages.
Inniss soon showcased his aerial prowess as he rose highest to meet Lee’s deep free-kick delivery, only for Chairboys’ captain Jacobson to acrobatically clear off the goal line with the last kick of the game in SE7.
Charlton: MacGillivray; Clare, Pearce (c), Famewo; Jaiyesimi (Burstow 84), Gilbey, Dobson (Inniss 88), Lee, Purrington; Davison (Leko 46), Washington
Subs (not used): Henderson, Souaré, Watson, Morgan
Booked: Clare 21 (foul on Hanlan), Pearce 90+4 (off-ball incident)
Wycombe Wanderers: Stockdale; Grimmer, Forino-Joseph, Jacobson (c); McCarthy, Scowen, Mehmeti (Wheeler 61), Obita; McCleary; Hanlan, Vokes (Stewart 90+2)
Subs (not used): Przybek, Thompson, Horgan, Akinfenwa, De Barr
Goal: Vokes 35
Booked: Mehmeti 33 (foul on Gilbey), Wheeler 69 (foul on Gilbey), McCleary 90+4 (off-ball incident), Obita 90+5 (off-ball incident)
Referee: Paul Howard
Attendance: 18,895 (873 from Wycombe)