Lucky, you can never outfly a hawk with a mavic. It just gave up. Best action is to ascent with full throttle. The birds know that it would take them a lot of energy to ascent with the same speed and generally give up. Most birds of prey use as little energy as possible to rise to their operating height, and use all the kinetic energy when they dive to hurl down like a rocket, going faster than any other bird. They hit them with an awful lot of energy so that the prey is instantly and permanently disabled. It's a one way thing, no escape. A falcon can rise very fast (but only when it needs to however). My closest friend is a full time professional falconer and I have been taught many things about birds of prey and bird behaviour in general.
A peregrine falcon has a max airspeed of almost 400 km/h, average diving speed is 320 km/h. Max horizontal speed 110 km/h. Always try to be higher than the falcon, it will loose interest.
edit: most hawk species reach similar horizontal speeds and dive with 250-300 km/h