No, Atticus didn't win his case. Because he presented his defense of Tom Robinson so effectively and proved Tom couldn't have committed the crime, Atticus was able to get the jury to take longer before announcing Tom's guilt. Atticus was able to take a few baby steps toward equal rights and justice in Maycomb, but in the end, Tom Robinson was found guilty of a crime he didn't committ and died because of it. What's important to remember is that this was the beginning of the civil rights movement in the U.S. Whenever anyone tries to change a system so deeply ingrained in society, he/she must sometimes settle for baby steps. Sometimes it takes years and years for great changes to be made, but it is with the first baby steps of success that we are able to make great strides of change.
I think that Atticus should have won, but didnt. He proved a very good point and they had no evidebce to say that Tom Robinson was guilty.