In 2010, when Best Coast released their debut album, Crazy For You, it was an infectious blast of California sunshine that was equal parts surf-inspired guitar and ’60s girl group vocalizing. One could be forgiven for imagining it was slated to be a, “Here today, gone tomorrow” fad. And oh, how wrong one would have been.

Playing to a sold-out Paradise crowd in support of their third release, California Nights, the duo of Bethany Cosentino and Bobb Bruno (augmented by drummer, Brady Miller; bassist, Brett Mielke; and guitarist/keyboardist, Joe Bautista) showcased a career that has grown remarkably from their early promise and which was wonderfully expanded by their touring members supplying an appropriately emphatic oomph to the act’s decidedly low-fi stylings.

With an eager bunch literally jumping in anticipation in front of the stage Best Coast leapt in with, “The Only Place,” the title track from their 2012 sophomore record. On record this is perhaps the best summation of the Best Coast ethos: an impossibly contagious hook powering a simple verse-chorus-verse pop song. Performed live with the extended supporting cast it took on a ringing electricity allowing guitarist Bruno room to flex. The result was a locked-in but remarkably higher-octane delivery that set the tone wonderfully for the set.

And that idea, of a band locked in but never laboring, was what made for such a solid, wire-to-wire set. Sure they occasionally misfired, such as the false start to, “No One Like You,” but even then Cosentino playfully pulled it off by commenting, “Well, now that you know what song it is you can all sing along.” She wouldn’t have to ask twice as an adoring audience hung on every word.

Cosentino is a confident front woman – be it leading the assembled in hand claps during, “Crazy For You,” or rocking out on rhythm guitar during the stand-out new track, “Fine Without You” – which has not always been the case. She even occasionally ditches the guitar now and her vocals on the magnificent, “California Nights,” (this is not a band without strong title tracks) approached torch singer status. It also lyrically reminded that Best Coast still enjoy getting high but also that they refreshingly seem to have a clearer view through the clouds these days.

For his part Bruno is a muscular guitarist and with Cosentino and tour mate, Bautista, backing his leads he’s free to spray noisier guitar. This worked terrifically on the obscurity, “Fade Away,” where the droning three guitar attack came surprisingly close to shoe-gazer territory. In the past Best Coast could occasionally meander into drowsier stretches but in Boston their focus was sharp and even a softer, sweeter selection like, “Do You Still Love Me Like You Used To?” benefited from it.

By the time that Best Coast cruised into the home stretch with the strong threesome of the dreamy, “Goodbye,” the exquisite “Jealousy,” with Cosentino plaintively crooning, “Why don’t you like me?” and the swinging, “When Will I Change?,” it was hard to imagine the band prior to bulking up their stage sound.

Much has been made of California Nights being the band’s first major label release (Harvest, an imprint of Capitol) and if having the backing to take three additional musicians out on tour is the result then the future looks exciting for Best Coast. Of course, as the evening’s ending tune, “Boyfriend” proved, a great song is a great song in any context and the smiling fans humming it on the way out spoke volumes to what has put Best Coast in their current enviable position.