Dion performed her signature ballad "My heart will go on" on a Las Vegas stage. While the fans cheered for her, there was only one person she was singing to.
At her family home a few miles away, her dying husband Angelil watched the performance via a live link from his bed, reports mirror.co.uk.
Riddled with cancer, he was too ill to go to his wife's live shows but his dying wish was for her to perform. He died in 2016.
She recalled: "It wasn't therapeutic for me, it was therapeutic for Rene.
"For him it was very important because I took a year off to take care of him but towards the end he said to me, 'I need to see you go on stage and sing, I want to make sure, I need to see it'."
The 51-year-old mother-of-three said of the final performances Angelil saw: "I didn't feel like partying or putting on short dresses and feathers. But what kept me going was that I thought of him. I did it for him.
"When I came home, he was so happy."
Angelil, who had discovered Dion when she was 12, suffered multiple health problems throughout the couple's 21-year marriage. He had a heart attack in 1991 at 49 and in 1999 was diagnosed with throat cancer but recovered after treatment.
Then in 2013 the disease returned. In September 2015, Dion announced that Angelil had only "months to live". He died of a heart attack in January 2016, aged 73.
( With inputs from IANS )