An encouraging first half hour was stopped in an instant as Pol Valentin was adjudged to have fouled his tormentor Josh Ginnelly in the box. From there things spiralled.
Wednesday were passive and unable to muster anything in the way of attacking promise - their defensive efforts scrappy and well punished.
It leaves the Owls still without a win this campaign having playes eight league matches - and two in the cup.
They are the only team yet to win a game after round eight of the Championship season.
Here are our player ratings from a horror trip to South Wales.
1. Devis Vasquez - 4
Made an excellent save to deny Lowe before the Swansea goal ruled out for offside. Away with the fairies on the ball at times, most notably when Jamie Paterson chased him down to fire into the side-netting.
2. Di’Shon Bernard - 4
Started a couple of attacks with strong balls from defence. Was part of a defence that looked all at sea and Swansea had joy in his channel.
3. Bambo Diaby - 3
Acted smartly to block an early Lowe shot but looked flat-footed. Flew in to smash against the crossbar on the hour. Couldn’t marshal a defence that looked appalling.
4. Akin Famewo - 5
Into the action early, stopping a dangerous Swansea attack. Caught in possession once or twice and like those around him, was slow to react to attacks. Won more tackles and headers than his teammates.