Interestingly that was Gatlin at or near his best (wind and altitude adjusted). It just shows what a rabbit Usain pulled out of the hat in the final.
Gatlin heat 9.83 at 2.1m/s wind = 9.93 basic
Gatlin semi 9.77 at 0.9m/s wind = 9.81 basic
Gatlin in Doha 9.74 at 0.9m/s wind = 9.78 basic
Gatlin in final 9.80 at -0.5m/s wind = 9.77 basic