Lily Tomlin crushes her best movie role in years in Grandma, playing her age (76) but not acting it in the least.No other performance lately kept me smiling so broadly, watching a buried national treasure recoup relevance one impeccably performed scene at a time. Tomlin is a joy to watch, so much that one wonders why more chances like this haven't come along since her Oscar nominated debut in 1975's Nashville. Tomlin, also enjoying a comeback on the small screen, is up for a Lead Actress Emmy Sunday for her performance on the Netflix show Grace and Frankie. Tomlin plays Elle Reid, a retired poet and fountain of scorn cruelly breaking up with a much younger girlfriend (Judy Greer) when the movie begins. Just a rebound fling after the death of Elle's longtime partner, a relationship that resulted in a daughter (Marcia Gay Harden), who is estranged and extremely uptight. So uptight that her teenage daughter Sage (Julia Garner) can't tell her workaholic mother about her unexpected pregnancy. Sage wants an abortion but doesn't have $600, so she looks to grandma Elle for help. Broke herself, Elle begins hitting up people for loans or paybacks, most of them left behind on her unfriendly terms. Elle doesn't suffer fools, which is what she considers most of humanity. Except for Sage. But she was stupid for not using a condom.Writer-director Paul Weitz (About a Boy) makes this one-city road trip movie into a prickly character study. Elle's depth of depression, fury and regret are defied by Tomlin's energetic portrayal of it, dripping with elderberry venom. Grandma is a very funny movie but mordantly so, with Tomlin gradually turning Elle's bitterness brittle.Weitz's episodic scheme is a mixed blessing, offering what amounts to thankless cameos for some actors (John Cho, Laverne Cox, Nat Wolff) deserving more to do. On the other hand, Weitz crafts a terrific sequence involving Tomlin and silver fox Sam Elliott, a reunion of former lovers full of unexpected dialogue and reactions. Elliott has never been better on screen, and that's saying a lot.Tomlin keeps the proceedings unpredictable, never letting on what's brewing behind those crinkly eyes and thin lips until it boils over. It's the sort of performance that saves movies. Grandma might not be worth visiting if not for her.Contact Steve Persall at [email protected] or (727) 893-8365. Follow @StevePersall.