Two goals in a minute gave Barwell the three points as Alvechurch were left frustrated at Kirkby Road.
Dean Holtham's side had made a good account for themselves, especially in the first half where they dominated, but Mitch Botfield's red card just before the break ultimately cost them.
Alvechurch started fast with Kyle Perry testing Barwell keeper Max Bramley from range. They did take the lead soon after however, with Ryan Wollacot heading home a Lewis Wright corner to register his first goal for the club. A minute later the ball was again in the net but Kyle Perry was deemed to be offside as the Church continued to impress.
Perry, Wright, and Zack Foster were all then denied by Bramley before the game changed. Botfield was shown a second yellow for a late tackle on Tristian Dunkley. This saw Church defend for most of the second half, with Brady Hickey firing wide and Joe Slinn denying Kai Williams.
Tolani Omotola then headed wide before Barwell secured the win. Declan Towers was left unmarked to head in and within a minute Williams had picked up the ball and slotted in the second.
Louis Monaghan then headed over Church's best chance as they were left with nothing for their efforts.