Rogue's right. Use glide and stay on its tail!
If this doesn't work then maybe use glide to get a bit of distance from the target and avoid using match-speed. Otherwise you're caught in an eternal loop of "almost had him". If you ever find yourself in a pattern like that, it's up to you to break it because the AI won't.
So, to clarify... If you're going in an eternal loop. And you find yourself in a situation where you can squeeze a few rounds off, flip around, squeeze another few rounds off, flip around again, squeeze another few rounds off, etc. Then use glide to break the pattern. You'll keep going in one direction but you can face the enemy and fire while keeping your distance (which stops the enemy running circles around you). The enemy AI usually stops the eternal loop maneuver and decides to go for you.
I know this was a problem for me in Tutorial 2.
Might add this to the guide later
(although I thought I had
Hope this helps!