Ten-man Wednesday held out for a hard-earned draw as play-off contenders Reading missed out on all three points.
Callum Paterson gave the Owls the lead before Liam Shaw saw red and ex-Owl Lucas Joao extended his purple patch in front of goal.
The Royals went on to dominate but a well-drilled home defence held firm to ensure both sides took a share of the spoils.
A lively opening saw chances at both ends, one that was missed and the other converted.
The Royals may well have felt frustration as they were out of the traps apace and could have taken the lead six minutes in.
Omar Richards threaded a fine ball through to Joao, who could only drag his shot across Joe Wildsmith and wide.
And the visitors paid the full price five minutes later as the Owls hit the front. Kadeem Harris found Adam Reach down the left and the cross was inch perfect for Paterson to neatly nod into the far corner.
Reading kept their composure and promptly came within a whisker of levelling. Michael Olise lined up a set piece 20 yards out and his curling effort smashed against the foot of the post.
But on the half-hour mark, the Owls suffered a blow as they were reduced to 10 men. Shaw’s challenge on Richards was deemed dangerous and the midfielder received an unwanted Christmas card.
That triggered a Royals onslaught, at the end of which was an equaliser from Joao two minutes before half time.
After Reach did remarkably well to clear a Richards effort off the line and Wildsmith acrobatically denied Alfa Semedo, Reading made the breakthrough to get back on terms.
Ovie Ejaria delivered a deep cross to the back post, where the Portuguese was on hand to nod home.
Wednesday welcomed the interval, in which Tony Pulis made a triple substitution, with Moses Odubajo, Dominic Iorfa and Joey Pelupessy all coming on from the bench.
And Odubajo was straight at the heart of the action, tangling with Richards in the box, but the infringement went Wednesday’s way.
Reading continued to probe - Olise brushed the top of the net with another set piece – and Joao was thwarted at the back stick by Iorfa.
Substitute Sone Aluko unleashed on the angle but was wide of the target and Wildsmith spooned an Ejaria long ranger clear.
It was all Reading in the closing stages and the Owls survived two more penalty scares to emerge with a third successive point.
Wednesday: Wildsmith, Palmer (Odubajo 46), Lees, van Aken (Iorfa 46), Börner, Reach, Bannan (Pelupessy 46), Luongo, Shaw (S/O 30), Harris (Kachunga 90). Paterson