"We were one and nothing has changed. We will always be one," she told the audience at the Colosseum on Tuesday, February 23.
The show began with a montage of pictures and videos of Angélil through the years, along with a quote from his loving wife: "I understood that my career was in a way his masterpiece, his song, his symphony. The idea of leaving it unfinished would have hurt him terribly. I realized that if he ever left us, I would have to continue without him, for him."
Then the curtains parted and Dion stood alone on the stage in a glittering black gown embellished with stars. And after the crowd gave her a standing ovation, she began singing "With One More Look at You," her voice breaking at times.
Afterward she had tears in her eyes as she addressed the audience.
"I did rehearse this song in my closet and it went way better than that," Dion said. "Through my life I only had eyes for my husband, who sat out here night after night. People thought that I was looking at him, but I didn't need to because every time I closed my eyes, I felt René on stage with me — whether he was seated in his seat right there, in the balcony, backstage or at home with the kids. He's always been on stage with me and nothing will ever change that."
Angélil, who was also her manager, "always surrounded me with the very best people possible," she continued. "I trusted him so much that I rarely had the chance to worry about anything. Now I guess it is just a natural impulse to constantly question myself: 'Would he let the kids play with these toys? And is this song too fast? Is this song too slow? Don’t talk too much.' It's pretty amazing that since he physically is no longer with me, he is even more present."
Describing her late husband as her "very best critic," Dion told the crowd, "he never told me what I wanted to hear, he told me what I needed to hear."
"He always made me feel that we were on our first date. Isn't that amazing?" she continued. "Never talking bluntly and always expressing himself in a soft and gentle way."
"I might not hear his voice yet, but I talk to him, I think of him all the time," Dion added. "I feel and I know he hears me, one way or another. I know he will give me a sign for his approval or not. And now I can feel that he is telling me to zip it and start singing."
And after a few words about Angélil in her native French, she launched into "Where Does My Heart Beat Now."
In a message posted on her website on Monday, February 22, the singer announced that she was dedicating Tuesday's show to Angélil and would be live-streaming the first 10 minutes of the concert on CelineDion.com.
"Join Celine and her fans in Las Vegas for a trip down memory lane, live at The Colosseum, to celebrate her return and witness Celine’s loving tribute to René," the message read.
The pair first met when Dion was just 12, and later married in an elaborate wedding ceremony in Montreal in 1994. They were parents of three children — son Rene-Charles, 14, and twin sons Nelson and Eddy, 5.
Angélil was diagnosed with throat cancer in 1998 and the "My Heart Will Go On" singer took a leave of absence from her Vegas show in 2014 to look after him.
But he insisted that she return to performing in August 2015.
"That first show, it will be fragile," she said at the time. "There will be moments. Of emptiness, laughter, awkwardness, tearing up."
Sign up now for the Us Weekly newsletter to get breaking celebrity news, hot pics and more delivered straight to your inbox!