You need to be careful when handling glass. In larger sheets it is very weak in a horizontal plane. It is strongest when it is in a vertical plane. (That’s why glass is always supposed to be shipped upright.)
The transition between horizontal and vertical is important because the glass sheet can break if it does not have the proper support. However, there is a tried and true method for laying glass down and turning it over.
Rest the glass on the edge of the bench, half on, half sticking off. Support both sides of the sheet. Then pivot it to the horizontal, still resting the middle of the glass on the edge of the bench as your fulcrum. This provides support at the middle during the transition from vertical to the horizontal of the bench top.