'Top Five' (R)

Chris Rock is one of the sharpest, funniest and most daring stand-up comics working today, an artist who uses humor for incisive social commentary about race and politics. But he’s never been able to break through as a movie star the way some fellow former Saturday Night Live cast members have. He has directed two movies (Head of State and I Think I Love My Wife), neither of which made much of an impact, and he has acted in countless junkheap comedies (including several Adam Sandler vehicles) that made little use of his talent. The fact that his most memorable role was a dramatic turn as a junkie turned informant in 1991’s New Jack City is proof that his brand of comedy, until now, hadn’t translated well to the big screen.

Top Five, which Rock wrote and directed, revolves around a simple premise: A comedian (Rock) longs to be taken seriously as a dramatic actor. On the day of the release of his new film Uprize!, about the Haitian slave revolt, he’s being followed around by a New York Times reporter (Rosario Dawson) who is writing a profile of him, and he’s planning to marry his reality-TV star girlfriend (Gabrielle Union) live on the air.

The first half of the movie, which alternates between hilariously vulgar, gross gags and some electric improvs and riffs by Rock and his cast of all-stars, has the crackle and pop of a live performance — it energizes you. Rock has always been a hugely likable presence who deserved better than co-starring in those lazy Grown Ups movies, and for a while, Top Five feels like he has finally made a comedy that nails much of his favorite subject matter, from African-American life to the insiders-only nature of Hollywood to the strings that come attached to fame and fortune. The film is loose and jaunty, and even if the story seems to be heading in a dozen directions at once, Rock’s appealing grin and everyman appeal hold the picture together. Top Five is without question the best cinematic showcase of his considerable talent to date.

Unfortunately, Rock falls into the trap that befalls so many studio comedies, taking a dramatic, sentimental veer in the last half-hour into alcoholism, unrequited love and secret revelations. Suddenly, the funny stuff cedes to tears and syrupy music, and we’re befuddled and confused. What happened to the cheeky, brash comedy we had been watching? Even subplots get abruptly dropped (Union’s bride-to-be character fares particularly badly). Top Five starts out with a bang (a fateful visit to Houston with an assistant, played by Cedric the Entertainer, is one of the most uproarious scenes in any film this year, and a cameo by a famous rapper totally kills, even though he only says one word). But the film ends with hugs and sniffles, as if Rock felt it necessary to give his movie some emotional weight. Sometimes, laughter is all you need.

Cast: Chris Rock, Rosario Dawson, Gabrielle Union, Cedric the Entertainer, Kevin Hart, Tracy Morgan, Whoopi Goldberg, Adam Sandler, Jerry Seinfeld.

Writer-director: Chris Rock.

A Paramount Pictures release. Running time: 101 minutes. Vulgar language, sexual situations, crude humor, adult themes. Playing at: area theaters.