La Fuente Mexican Restaurant, a downtown Brentwood institution, is about to enter its teenage years, but just when customers thought they knew everything there is to know about the popular restaurant, in comes its cousin, La Fuente Bar and Grill.

Passersby have watched La Fuente blossom in its 13th year by the addition of a spacious patio highlighted by a picturesque fountain that resonates casual tranquility and an exultant family-friendly atmosphere. Customers have been enjoying the new expanded outdoor dining experience this summer, but that’s only the beginning of owner Oscar Olvera’s vision.

Earlier this month, Olvera opened La Fuente Bar and Grill, a rustically charming extension of the main restaurant next door. The bar and grill offers the same delicious Mexican cuisine that La Fuente is known for, but the menu also includes pizza and a wide selection of appetizers such as jalapeño poppers, French fries and fried calamari. While the restaurant closes at 9 p.m., La Fuente Bar and Grill stays open later so customers can grab a light dinner or socialize with friends after a busy day at work or after catching a movie.

“I’ve been waiting for this moment,” said Olvera. “I’ve wanted to make a change for a while now, and it’s finally here. I’m nervous, though. I’ve been working on this (the expansion) for months, but it’s time. I think people are ready for a place like this.”

When Olvera got word that the space next door to his restaurant had opened up, he knew it was a sign. He had considered relocating to a bigger location at the other end of town, but when the space became available, he knew it was time to open the bar and grill that he’d been imagining for years. The bar and grill offers an after-hours location where guests can drink, dine or just hang out. But customers don’t need to wait until late evening to enjoy the new La Fuente experience. The bar and grill opens at 4 p.m. and hosts a happy hour from 4 to 6 p.m., when guests get a 25-percent discount on draft beers, margaritas and appetizers.

On weekends, bands serenade guests on the patio, and customers inside and out get up to clap their hands and move to the beat. John Dilao will perform tonight from 6:30 to 9:30 p.m., DJ’s Daley Entertainment will keep the energy going from 10 p.m. to midnight, and Les Edwins will perform on Saturday from 6:30 to 9:30 p.m.

“There aren’t a lot of places to go to eat late at night,” Olvera said. “Most restaurants close early, so if you’re out with friends and want to grab a late dinner, your only option is fast food, and that’s not good for you. With La Fuente Bar and Grill, we have light appetizers or you’ll be able to get a taco, burrito or try one of our Mexican pizzas.

“By staying open later, we’re keeping the energy alive downtown, and that seems to be what the city is going toward with the new downtown plan. I couldn’t wait, though. As soon as opportunity presented itself, I had to go for it. We’ve had a soft opening and people really like it. They love the patio and the live music, and of course they love the food. It’s the same quality flavorful meals that people have come to expect from La Fuente. Now, customers have even more variety.”

La Fuente Bar and Grill, located at 642 First St. in Brentwood, is open Sundays through Wednesdays from 4 to 10 p.m.; Thursdays from 4 p.m. to midnight; and Fridays and Saturdays from 4 p.m. to 1:30 a.m. The original La Fuente Mexican Restaurant, adjacent to the Bar and Grill, is open Mondays through Thursdays from 10:30 a.m. to 9 p.m.; Fridays from 10:30 a.m. to 9:30; Saturdays from 8:30 a.m. to 9:30 p.m.; and Sundays from 8:30 a.m. to 9 p.m. For more information, call 925-516-2233.