McNeill put the hosts in front on four minutes after Manchester United loanee Harry Amass had burst into the box and cut the ball back for his unmarked team-mate to curl into the back of the net.
Whiteman – back in the Preston starting XI after suspension – quickly equalised from outside the area when the ball was cut back to him from a corner after Ethan Horvath had denied Alfie Devine and Thierry Small in quick succession.
Undeterred, the lively Owls went back in front when McNeill, another graduate of Manchester United’s academy, claimed his second with a close-range header from Liam Palmer’s cross.
Wednesday kept the pressure on in the first half, with Iversen denying Yan Valery and Bailey Cadamarteri, but could not make their dominance count further.
Dobbin equalised just shy of the hour mark when he nodded in from a corner after Liam Lindsay made first contact with the delivery at the far post.
Henrik Pedersen’s side were handed a golden opportunity to earn their first win in 12 when Odeluga Offiah handled in the area, but Iversen guessed the right way to keep out McNeill’s spot-kick.
They were punished three minutes later when Frokjaer-Jensen found the bottom corner from the edge of the area.
Another substitute almost had the final say, but it was not to be for Nathan Redmond on his Wednesday debut as his late effort curled wide, leaving his side on minus four points.
