NEW YORK (AP) -- Demi Lovato celebrated six years of sobriety at a concert in New York with tour mate DJ Khaled, whose powerful words brought the pop star to tears.
Lovato performed Friday night at the Barclays Center in Brooklyn, telling the audience that March 15 was a proud day for her.
DJ Khaled played the role of preacher, life coach and best friend as he offered words of inspiration, motivation and admiration to Lovato, who has been open about her issues with drugs and alcohol. He told the crowd "this is a special day" and repeatedly said "happy birthday" to Lovato, as she began to tear up.
"Every time I see you I say, 'Man, this is a strong queen,'" he said. "What you've overcome through trials and tribulations, through dark clouds, you found the sunshine, and now the sun is shining on you forever."
"You inspire me," Khaled added.
DJ Khaled and R&B singer Kehlani, another tour mate, encouraged the crowd sing "Happy Birthday" to Lovato in honor of her sixth year of sobriety.
The crowd then chanted "Demi!" as she sat down by the piano and dabbed her eyes with tissues handed to her by a crew member.
"Six years ago, I was drinking vodka out of a Sprite bottle at 9 in the morning, throwing up in the car," Lovato said. "So, I took a look at my life and I said, 'Something has to change, I've got to get sober.' So, I did."
"Thank you for being a part of saving my life. I love you guys," she added before performing the song "Warriors."
Lovato struggled with an eating disorder, self-mutilation and other issues, entering rehab in 2010. The 25-year-old has spoken out about her battles over the years, detailing her recovery in the YouTube documentary "Simply Complicated," which was released last year.
Grammy-nominated Kehlani, who has also been open about her personal struggles, thanked Lovato and said she's honored to know the singer.
"As a 22-year-old woman, you represent me, you represent every single women in this room and even every single young boy," the singer said. "You are 100 percent yourself, and that is so rare in this world and this industry."
Lovato's concert took another emotional turn when she performed the song "Father," saying this was the first tour she's been able to sing the song. Her biological father, who she has described as mean and abusive, died in 2013.
"I had love for him and I forgave him," she said. A photo of her father holding her as a baby closed the performance.
Lovato ended the concert, backed by the New York City Gay Men's Chorus, with the songs, "Sorry Not Sorry," and "Tell Me You Love Me."