Review: How Harry Styles accidentally saved a One Direction concert

“R.I.P. Zayn,” read the sign in black and red ink, an appropriately dramatic send-off for a teen idol known for triggering life-or-death emotions.

But the message to Zayn Malik – the One Direction member who abruptly quit this mega-popular British boy band in March – didn’t come from his former bandmates Thursday night at Qualcomm Stadium, where the group launched the North American leg of its latest world tour. The message was held aloft by one of the tens of thousands of ultra-devoted fans in the audience.

As for a similar sentiment from Malik’s old pals? Nothing. Not even a word.

Well, duh: To acknowledge a chink in the armor of pop stardom is to acknowledge the existence of armor in the first place, and in a sense the whole point of One Direction is the group’s natural imperturbability – the way these guys simply move through the world unbothered by all that’s happening around them.

That quality, far more than the music, is what distinguishes One Direction from its more animated boy-band predecessors. Where ’N Sync and the Backstreet Boys used flashy costumes and choreography to reflect their fans’ excitement, One Direction – famous for not dancing and for wearing ratty T-shirts like the one Harry Styles rocked Thursday -- play it cool, which of course only drives the fans crazier.

So you can see how a heartfelt tribute to the absent Malik, or even a show of bitterness over his departure, would have felt off-brand.

Still, such a display might’ve livened up the show, much of which suggested that after five years the band’s unflappability is beginning to harden into boredom. Certainly, Malik looked bored last year when One Direction played the Rose Bowl. And here the group’s remaining four – Styles, Niall Horan, Liam Payne and Louis Tomlinson (who, rather delightfully, wore a Black Sabbath tee) – seemed to have contracted their ex-bandmate’s over-it attitude as they ran through hits from their four albums on a massive stage similar to the one they had on their 2014 tour.

“Our job tonight is to entertain you,” Styles told the crowd not long into the two-hour show. “And your job is to have as much fun as you possibly can.”

The nearly nonstop shrieking inside the stadium made it clear that both sides were living up to that deal. For the first time, though, One Direction’s job really looked like one; there was something routine, as opposed to offhand, about the band’s performance, even as Payne kept repeating how psyched he was to be starting another tour.

At least that was how the show felt until a remarkable sequence provided a spark of electricity late in the concert.

It began with an unusually barbed aside from Styles clearly inspired by his San Diego surroundings. “Does anyone like dolphins?” he wondered. “Don’t go to SeaWorld.” Then he asked the crowd to clap out the beat for One Direction’s song “Through the Dark” – a typical pop-show custom, except for Styles’ dogged determination.

“There’s a dad refusing to clap his hands,” he announced, pointing into the audience. At that, a cameraman swiveled to get a close-up of a chagrined-looking father, whose face instantly filled the giant video screens flanking the stage.

“That’s actually a different dad,” Styles said after he got a look. Two old guys at a One Direction show unwilling to play along? “Pretend you’re at the Eagles,” he told them. Zing!

Pop god swagger now bursting out of his skinny jeans, Styles pumped his fist and strutted toward a row of fans when suddenly he appeared to get caught in a cord and took what might have been the most elaborate onstage fall I’ve ever seen. (By Friday morning, it had become an Internet meme.) With his bandmates not even bothering to hide their laughter, Styles stood up, bowed exaggeratedly and got on with the business at hand.

It was endearing. It was hilarious. But most of all it was unexpected -- just the thing to liven up another night at the office.

Twitter: @mikaelwood