The Blues keeper dived to his right to keep out Dean Parrett's penalty in the sixth minute of stoppage time after Fred Onyedinma scored twice, either side of efforts from Tom Pett and Parrett.
Gareth Ainsworth handed starting berths to Sam Saunders and Nico Yennaris, with the pair having joined on loan from Brentford 24 hours earlier, while Danny Rowe replaced the suspended Aaron Pierre in defence.
The hosts started well and saw Fred Onyedinma’s 20-yard snapshot saved by Chris Day, before the lively striker’s low drive was deflected into the side netting after Paul Hayes neatly back-heeled the ball into his path.
But you can’t keep the Millwall man quiet for long and he opened the scoring on 11 minutes when Paul Hayes set him free with a sublime pass and after Day made the decision to rush out, Fred tucked the ball past him and saw it roll into the net.
The Blues were comfortably on top, with Yennaris seeing plenty of the ball in the middle of the park and Saunders looking to pull the strings out wide.
But Boro soon got their act together and began to apply pressure to the Wycombe backline, and earned their equaliser on the half-hour mark when Chris Whelpdale escaped down the right and delivered the perfect cross for Tom Pett to send his header back across goal and into the net.
The leveller put the buffers on the Chairboys’ attacking intents and in fact Boro became the stronger force, but Ingram was equal to efforts from Pett and Dean Wells.
However, he was helpless when Dean Parrett’s stoppage time free-kick found its way through a crowd of players and nestled in the far corner to give the visitors the lead at the interval.
Wycombe came out pumped up after the break and enjoyed the greater possession without being able to test Chris Day; Sam Saunders dug an effort wide before Paul Hayes’ cross-shot missed the target and the onrushing Wanderers attackers.
As the game descended into an ugly scrap, one man kept his head – and put it to good use – when Fred Onyedinma rose at the back post to crash home a header from Joe Jacobson’s corner with 20 minutes remaining.
And the home fans had further reason to be optimistic of a comeback win when Chris Beardsley received his marching orders for a second yellow card with 15 minutes still to play, having committed two poor fouls on Sido Jombati.
Wycombe continued to knock on the door of the visitors and came close to a winner when the ball fell for Matt Bloomfield in stoppage time, but his difficult volley flashed just wide. Then Danny Rowe’s clipped cross into the box was glanced wide by Onyedinma as the visitors held on – just.
And then came the climax to the drama in the very last minute as Ben Kennedy went down inside the box and prompted referee Simpson to point to the spot. Up stepped Dean Parrett, but Matt Ingram flew to his right to make a fine save and salvage a point which could prove to be crucial in the race for promotion.
Wycombe: Ingram, Jombati, Jacobson, Mawson, Rowe, Saunders, Bloomfield, Yennaris, Wood, Hayes, Onyedinma.
Unused subs: Richardson, Fletcher, Murphy, Ephraim, McClure, Holloway, Craig.
Stevenage: Day, Deacon, Dembele, Henry, Wells, Pett, Parrett, Walton (Lee), Martin (Kennedy), Whelpdale, Beardsley.
Unused subs: Beasant, Bond, Johnson, Conlon, Andrade.
Referee: Mr J Simpson
Attendance: 3,664 (416 from Stevenage)
Winning 50/50 Draw Number: 139174
Prize Money: £695.00