Tyreeq Bakinson's goal late in the game was enough to give Sheffield Wednesday a 1-0 victory over Charlton.
Barry Bannan had a chance for the hosts after only two minutes, glancing a header just wide.
Charlton then enjoyed a good spell, with Albie Morgan having an effort saved by David Stockdale while Scott Fraser and Steven Sessegnon both put shots over.
There was another chance for Charlton when a defensive mix-up let in Corey Blackett-Taylor, but Liam Palmer got back to clear off the line.
Bakinson threatened to force the breakthrough shortly before he found the net.
The goal came nine minutes from time when Windass crossed from the right and Bakinson powered a header into the net.
Windass then picked up a loose ball, ran into the box and squared to Sow, whose effort was blocked.
The pair combined again in stoppage time, with Sow finding Windass on the edge of the area, but he fired over.