League leaders Leicester were heading for three more points on the board until Wednesday got their just rewards right at the last.
Abdul Fatawu gave the Foxes a first half lead and despite knocking hard on the door, the Owls could not find a way through – until Jeff Hendrick climbed off the bench to snatch a thoroughly deserved equaliser.
Right from the start, Danny Röhl's side were on the front foot. Indeed, less than 30 seconds were on the clock when the Owls had a golden opportunity to put down a marker.
Barry Bannan picked the pocket of Ricardo Pereira 20 yards out on the angle, advanced on goal, but guided his shot just past the far post.
Bannan swiftly tried to make amends, this time robbing Harry Winks in a similar but more central position, squared to Callum Paterson, whose low shot was smothered by Mads Hermansen.
And the Foxes promptly capitalised, scoring from their first attack of note on 23 minutes.
Stephy Mavididi stood up a looping cross that fell to Fatawu at the back stick and the Ghana international made no mistake with a sweeping half volley.
But the hosts were undaunted and continued with forward momentum. Bailey Cadamarteri, making his first start, had a vicious hit charged down by Jannik Vesteragaard and Hermansen kept George Byers at bay early in the second half.
Still the Owls pressed but as the contest wore on, Leicester comfortably absorbed the pressure and brought down the tempo.
Only occasionally did they venture into Wednesday’s half, seemingly content with the one-goal advantage.
And they were made to pay in stoppage time as the Owls finally broke through.
Paterson nodded a high ball into the path of the advancing Hendrick and the Irishman prodded past Hermansen to salvage a well-deserved point.
Wednesday: Dawson, Iorfa, Diaby (Palmer 61), Bernard, Famewo, Johnson, Vaulks (Fletcher 78), Byers (Buckley 72), Bannan (Hendrick 78), Paterson, Cadamarteri (Musaba 61)