For moving subjects in lowlight, it sometimes helps to just use manual focus based on the relative distance of the subject. If it is more 2 meters away you can try manual focus at infinity, I find that it is reasonably sharp.
Alternatively, if you can manage to tap on the subject and successfully get a focus lock, then after pressing the shutter you can continue to hold down the shutter for burst-mode kind of shooting. This way, the focus lock will remain in place rather than having it recalculate the focus again everytime.
If all else fails, use the Smart Cam. It works very well for fast moving subjects in terms of getting the correct focus and the shutter speed will also freeze the movement. You will most likely be able to nail that shot. However, faster shutter also results in much higher ISO which has more noise in very lowlight conditions. The other downside is that you can't use it with flash.