nate hubbard and sweet water oak hang back in fifth place.horses round the far turn, chapman makes a break for the lead. >> current lady cruising on by on the outside. >> and now tom chapman's got his eyes on that first place finish. >> back in front current lady takes the lead. >> but nate's horse, sweet water oak, is coming up from behind. in no time at all, hubbard is riding side by side with chapman. >> you can hear him yelling at his horse, i can hear him coming up from the inside. >> current lady on the inside, on the outside sweet water oak. >> my filly started to drift in just a little bit. right when i reached up to grab her is when just a split second too late is when she clipped tommy's horse. >> i could feel my filly take kind of a funny step. and i thought, god, we collided. >> sweet water oak stumbles. >> sweet water oak loses the rider. current lady in front. >> the next thing you know, she's popped back up and i just happened to be hanging on her neck. >> riders, please watch out. >> nate hubbard manages to stay on the horse a