Second half goals from Liam Waldock and Bailey Cadamarteri earned the Owls Under-23s a point at Swansea in the early Monday kick-off.
In an action-packed Professional Development League encounter, Wednesday went in at the break 2-0 down but fought back in the second period to leave South Wales with a draw.
Waldock’s powerful drive set up a grandstand finish with 15 minutes left on the clock and it was a milestone moment for Cadamarteri five minutes from time, as the youngster registered his first goal at Under-23 level to equalise.
The late drama continued well into stoppage time as Paulo Aguas picked up his second yellow of the game eight minutes into time added on, but the Owls held out to post a hard-fought point on the road.
Swansea hit the front in the 11th minute as Wednesday failed to clear from a corner and Joe Thomas was on hand at the back post to prod into the net.
The hosts doubled their lead just past the half hour mark with a blistering strike from Tivonge Rushesha.
The defender collected possession 45 yards from goal and surged upfield before rifling into the top corner from range.
It was almost game, set and match on 68 minutes when Swans midfielder Joel Cotterill rattled the woodwork from distance but five minutes later, the Owls were well and truly back in the contest.
Ryan Galvin’s cross from the left was cleared as far as Waldock on the edge of the box who caught the bouncing ball sweet on the half volley and smashed home low into the bottom corner.
The visitors were buoyed having pulled a goal back and the equaliser arrived in the 85th minute.
Galvin’s persistence on the left to get past his marker opened the space to deliver into the box where Cadamarteri was perfectly placed to guide the ball beyond the outstretched arm of Swans keeper Nico Hansen.
Wednesday almost snatched the win five minutes into added time but Leojo Davidson was denied by a good stop from Hansen, before Aguas was dismissed for a second booking on 98 minutes in the final action of note.
XI: Charles, Dawodu, Agbontohoma, Ashman, Galvin, Aguas, Waldock, Trialist (Glover 70), Trialist, Zottos (Davidson 80), Cadamarteri