2 things happen when horses win their last start.
1/they go up in weight[which is not too bad if racing similar class].
2/they come down in weight and too far up in class[this could be a trainers wishfull thinking or he is telling you the horse has a lot more ability than he has shown].
Look at the horses that ran 1st 2nd last start and coming back to a more suitable class this start.CHEERS