Marc Anthony broke down in tears at his sold-out concert in Miami on Friday night… but it’s not why you think!! Find out what happened after the jump!

Wendy L.

(People)

It may have been tough summer but Marc Anthony had the total support of his fans Friday night at his sold-out concert at Miami’s American Airlines Arena.

And they showed him that immediately as they sang “Happy Birthday” – Anthony turned 43 on Friday night – immediately after he took the stage. The surprised singer fell to his knees, teary-eyed, in thanks.

Then it was his turn to sing.

Performing mostly in Spanish, he kept the enthusiastic audience on their feet all night. Hinting at his recent heartache after thebreakup of his marriage toJennifer Lopez, Anthony introduced his song “Until I Met You” (“Hasta Que Te Conoci”) – about suffering in love – and called it “complicated.”

He also thanked the audience for “all your love and support, especially this year; it means a lot to me.”

Later in the evening, Anthony’s teenage daughter, Ariana (with ex-girlfriend Debbie Rosado), presented him with a three-tier, black and white birthday cake, while the crowd serenaded him once again.

Said Anthony: “Who in the world could say they’re spending their birthday like this? I’m a very lucky man.”

A Midnight Birthday Bash

Around midnight, the singer headed to a private birthday party – without a date – at Club 50 inside Miami’s Viceroy Hotel. Inside were about 150 close friends. The bash was sponsored by Kohl’s, where Anthony has a clothing line.

Anthony stuck around for about an hour – plenty of time to mingle with guests and cut his custom cake designed by Geof Manthorne of Baltimore’s Charm City Bakery.

When guests asked the singer what he wished as he was blowing out the candles, he replied that he “already had his wish.”

After Anthony cut his cake, he told his friends he was issuing an “executive order to stay, drink as much as you can and party all night.” But it didn’t apply to him as he had to get some rest before the rest of his weekend concerts.

“I feel like I am home,” he told his party guests, getting emotional. “Thanks for showing up. It’s mind-boggling.”