Perhaps I'm being over generous, or I'm just in a good mood, but I had a hard time giving this film any serious criticism. It is not the next Raging Bull, and it isn't trying to be. This is a simple story of changing your ways, and redeeming yourself for past mistakes. It uses the backdrop of a very successful fighter falling on hard times (mostly his own fault) to communicate that message, but it doesn't make it any less powerful.
As usual, I only remember that Forrest Whitaker was in the film after the fact. Jake Gyllenhaal breaks type. Though we've seen him do physical transformations similar to this before, such as Jarhead, and even Prince of Persia, this is an emotional departure for him. We don't like the character of Billy starting out in this film. That is what makes what follows all the more compelling.
I wish I could go into greater depth about this, but there are spoilers that I simply don't want to cover, and this is a short review.
I don't really care for Antoine Fuqua's work. That is to say, I'm not some fanatic fanboy. Training Day is a good film. The Replacement Killers, and Tears of the Sun are even better. I believe Southpaw is his best film since Tears of the Sun. I'm sure there's a myriad of rabid fans who'd like to tear me apart and tell me otherwise, but that is the way I see it. Needless to say, just because a director made a weak film previously, doesn't mean you should discount his efforts entirely. Every great filmmaker has his/her day, and also failures.
Southpaw is a very strong film that tugs at your heart. Gyllenhaal gives a fantastic performance that is somewhat limited by the language he is given in the script, and while I don't think it's going to earn him an Oscar, I can very well see Gyllenhaal exploding relentlessly with abandon in future film roles in which he will, absolutely, win the coveted golden statue.