A major Manhattan power outage spread south to Madison Square Garden on Saturday night, plunging the Jennifer Lopez concert into darkness and evacuating the venue.

Taking to Instagram, a “heartbroken” JLo apologized to concertgoers.

“I just don’t even know what to say. I just want you guys to know that you’re gonna get your money’s worth — that we are going to come back and do an amazing show for you. I am so sorry that this happened,” she said.

“I love you. I’m sorry. And I’ll see you all very soon.”

The “Love Don’t Cost a Thing” singer also thanked the Madison Square Garden venue staff.

“The building handled it really well. They did the smartest thing for everybody’s safety,” she said.

Reports from disappointed fans began pouring onto Twitter shortly after 9 p.m., as the outage — originally confined to the Midtown and the Upper West Side blocks south of 72nd Street — spread south to 14th Street.