Before "Southpaw" develops much of a plot, it showcases Jake Gyllenhaal's scowling, bloodied face. Captured in unsettling slo-mo, his mouth agape, he unleashes a fearsome battlecry and heads straight for the camera. It's a frenetic snapshot of intensity that suggests Edvard Munch's "The Scream" in the boxing ring, and one of the only times when the movie escapes the boundaries of its formulaic material. In that brief moment, it offers a viscerally engaging portrait of masculine belligerence driven to its hardiest extremes. But Gyllenhaal's alarmingly effective presence is enough to act circles around the soapy narrative of a fallen athlete's comeback so tightly that it crumbles in the very first act.