Coventry came close to an unwanted treble until Wednesday scored right at the last to force yet another clash between these two familiar faces.
For the third time inside a month, the Owls and the Sky Blues went head to head – this time in the Emirates FA Cup – and new recruit Victor Torp had the Midlanders on the way to victory with a peach of a strike on the verge of half time.
But Wednesday had the final say as Djeidi Gassama crowned an impressive performance with a late, late leveller.
Danny Röhl and Mark Robins made six changes apiece following the second match of the trilogy last weekend, with the Wednesday boss handing teenage goalkeeper Pierce Charles a maiden senior appearance.
Elsewhere, Iké Ugbo made his full debut, while Momo Diaby was given a starting shirt.
Both sides showed attacking intent from the off. Matt Godden spooned over the bar at one end before the lively Gassama fired wide at the other.
Kasey Palmer mirrored the earlier attempt from Godden as Coventry countered from a pressing Owls dynamic.
Gassama, making lightning bursts from the engine room, was the best player on the pitch in an opening period full of enterprise.
Time and again the Frenchman terrorised the Sky Blues’ defence, who struggled to combat Gassama’s pace.
Coventry had threats of their own, though, as was evidenced when Josh Eccles volleyed over the top from a clever set piece.
But the visitors went one better a minute before the break, and a moment to remember for Torp.
The Dane picked up possession 25 yards out and unleashed a blistering hit that flew past Charles to give his side the upper hand.
Ellis Simms missed a gilt-edged chance to double the lead immediately after the restart before the Owls hit back with Ugbo rattling the woodwork from distance.
Ugbo was inches away moments later, clipping a cute ball from Gassama on to the roof of the net.
The cup-tie calmed as the second half wore on. Coventry seemed content to play on the break as Wednesday pushed for an equaliser but Ben Wilson remained untroubled between the Sky Blues’ sticks.
That was until the 85th minute as the Owls finally made the breakthrough.
Gassama cut in on the angle and fired a low drive that shaded the post and beat the scrambling Wilson.
Still there was time for both goalkeepers to come to the rescue in a grandstand finish.
First, Wilson instinctively denied Ashley Fletcher with his feet, then Charles thwarted Jamie Allen from close quarters before the curtain came down on the Owls v Coventry part III – and part IV follows the week after next.
Wednesday: Charles, Valentin (Siqueira 81), Bernard, Famewo, Johnson, Gassama, Diaby (Palmer 81), Bannan, Musaba (Wilks 73), Cadamarteri (Fletcher 73), Ugbo (Smith 61)