Glapwell had an early chance when Neil Grayson was denied by visiting keeper Curtis Alden.
But the visitors took the lead from the spot on 22 minutes when Alex Wood stepped up and dispatched the penalty home after Andy Coverdale was caught by Ashley Grayson in the area.
The lead was doubled in fortunate circumstances just minutes later when Ryan Hopkins' attempted clearance struck Rob Dodson and flew into the net.
Westella made sure of the win on 72 minutes after Hopkins had brilliantly denied Chris Spinks, the ball fell to Garry Flounders who had a simple tap-in.
Overall, a deserved victory for the visitors but Glapwell were in no way outplayed as the visitors returned to the top of the table after other results while Glapwell are now guaranteed a sixth-place finish.
Glapwell have just two games remaining, both at home, starting on Monday against Thorne Colliery, 3pm, before hosting Harworth Colliery on Saturday, 3pm.
Full match report and photos to follow.