Cancer-stricken Olivia Newton-John has a new reason to fight, RadarOnline.com has learned exclusively, after daughter Chloe Lattanzi secretly rushed to the altar as a result of her famous mother's horrific diagnosis!

“Seeing her beloved daughter get hitched has given Olivia a reason to live a little longer,” spilled a source. “There’s nothing more she could possibly ask for right now — except maybe a grandchild!”

Lattanzi, 31, started dating James Driskill in 2009, and the two got engaged the following year. But they hadn’t started making wedding plans until 69-year-old Newton-John revealed her devastating stage 4 cancer diagnosis in May.

followed by breast reconstruction, vowing at the time, “I’m going to beat this thing. I have to — for Chloe.”

Chloe — whose father is dancer/actor Matt Lattanzi — was only six at the time.

Miraculously, she saw her mom endure surgery and chemotherapy, and bounce back with a clean bill of health.

tried homegrown marijuana, relying on cannabis oil to ease her pain.

Chloe even reached out to fans, begging for a spiritual lift to save her ailing mom.

“Will all of u send healing prayers for my mom’s back please,” she asked on Instagram.

to brain cancer in 2013.

Although the future looks bleak for Olivia, Chloe’s secret wedding is “the best medicine she could have at this point,” said a close friend.

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