"End of Watch" is 10 cups of coffee in cinema form, a visceral punch not for the faint of heart. Writer/director David Ayer (who scripted "Training Day") brings a rough, aggressive energy to the picture, staying within the broad outlines of the buddy-cop formula but investing the characters with no-bull authenticity.

Jake Gyllenhaal plays good-natured LAPD officer Brian Taylor, whose ever-present video camera sets up the premise that we're viewing a found-footage film. In the locker room he drags his half-dressed squad-car partner Mike Zavala (Michael Peña) into the frame, and the way Mike elbows his way back out again sets the tone for the pair's trash-mouthed macho bickering. They're a good-cop/good-cop team trolling the hot, hard streets of South Central Los Angeles.

The film has an appealing way of undercutting police thriller clichés. Mike would usually be a supporting player, with Brian taking the lead. In this film, the Mexican-American isn't the sidekick. He's savvier, married, with a kid on the way, underlining his status as a mature figure with moral responsibilities of his own.

Neither guy is the other's comic relief. They're both cut-ups when the mood is light and heart-attack serious otherwise. Both of them are good at their work. Both feel a tension between their home life and job. Anna Kendrick plays Brian's supportive but concerned girlfriend, Natalie Martinez is Mike's feisty, pregnant wife, and the domestic details ring true.

The actors are in top form. Peña merges seamlessly into his tough, soulful, funny role. Gyllenhaal, still movie-star handsome even with a shaved head, looks less like he's playing a cop and more like he might be one. When the action shifts into overdrive as a Mexican cartel targets the partners, we're deeply invested, making the vivid violence more than empty thrills.

While Roman Vasyanov's turbulent cinematography often captures vantage points no carry-along camera could record, the virtuoso handheld chase scenes, shootings and car wrecks are electric with urgency. The film's look is a sordid naturalism rendered with a directness rarely encountered. When the partners plunge into a burning building to rescue two abandoned babies, or their police cruiser slams into the tail of a getaway van, the danger is immediate and compulsively watchable.

Ferociously gritty and unsentimentally tough, the movie is a running battle between the idealism of its urban peacekeepers and fatalism about the ability of a small blue militia to pacify war-zone Los Angeles. The actors' outstanding work in spasms of ferocity and moments of gentleness makes "End of Watch" a victory of craft over clichés.


three 1/2 out of four stars Rating: R.