Anis Mehmeti scored his first goal in a Wycombe shirt and in professional football to grab a late equaliser against QPR, under the floodlights at Adams Park.
The visitors opened the scoring in the first half after Jason McCarthy unintentionally put the ball past Allsop after the defender attempted to clear the ball, following an Ilias Chair cross.
After the break, Wycombe looked the better of the two sides with Daryl Horgan and Scott Kashket missing chances to level the score early on.
With two minutes to go of normal time, Anis Mehmeti scored his first goal in Chairboys colours to level the game after beating his man and hitting a fine strike into the bottom left corner, meaning the points were shared.
Gareth Ainsworth has a long history with QPR, having played for and managed the Rs in his 7 years at the West London club.
Now in charge of The Chairboys, in his 11th year at Wycombe, Ainsworth selected Nick Freeman to replace the suspended Alex Pattison as Bayo Akinfenwa captained the side.
The Chairboys started quickly with Akinfenwa and Scott Kashket combining neatly. Kashket was able to create some space to take a shot at QPR's Seny Dieng, but it was straight at the Swiss keeper.
Rob Dickie kept Wycombe honest, rising highest at a corner, attempting to loop Ryan Allsop, but the Wycombe keeper was able to turn it behind with a fine stop.
Geoff Cameron was next to test Allsop, as the American tried his luck from range which brought out a diving save from the Wycombe shot-stopper.
Out of nothing, QPR took the lead after Ilias Chair delivered a cross into the box and Jason McCarthy, trying to clear, got a deflection on the ball and inadvertently put it past Allsop.
Wycombe came close to equalising almost instantly as Jacobson found Akinfenwa’s head, but his shot narrowly went over the bar. It meant the visitors went into the break with a one-goal advantage.
Following the restart, Allsop was called into action to make a fantastic stop to keep out Dickie’s header from a free-kick, diving to his left-hand side to put the ball behind for a corner.
A few moments later, Scott Kashket missed a great chance to equalise with a fine diving header. His attempt went just over the bar with the goal open after the keeper was down, having parried Horgan's shot just before.
The Irish international had the next shot on goal, after breaking through QPR’s backline to find himself one-on-one with the keeper. However, Dieng was able to block Horgan’s strike, hitting the side netting.
With Ainsworth looking to roll the dice in the final stages, his changes included bringing on 19-year-old Anis Mehmeti, Uche Ikpeazu and Fred Onyedinma, as Wycombe went looking for someone to spark the game into life.
It would be Anis Mehmeti who would make the game-changing move, scoring his first goal in professional football and for the Blues, with just two minutes until the 90th.
The attacker took on his man and hit a strike into the bottom left-hand corner from just inside the box and although Seny Dieng managed to get a hand on it, the QPR keeper couldn’t keep it out.
The Chairboys kept battling for a very late winner, but ultimately the game ended level with 19-year-old substitute Mehmeti making the difference.
Wycombe will take a point into their next game against Bristol City on Boxing Day.