most lift is not generated above the wing but due to angle of attack which is the angle of the wing relative to the flight path.
As the angle of attack is increases, the point of minimum pressure moves forward and the size of the adverse pressure gradient increases.
btw. In most most airfoils zero angle of attack and zero lift axis differ. The wing generates lift even without the angle of attack. Chambered wings are exception to this.
http://flighttraining.aopa.org/magazine/1998/November/199811...
The fact is that the percentage of lift that is attributable to angle of attack is far greater than that due to reduction in air pressure across the curved part of the wing.