A Perth retiree is looking forward to buying her first home and giving back to a charity that once helped her after winning a staggering $6.39 million Saturday Lotto prize.

The Bassendean woman in her late 70s wasted no time in claiming her prize, arriving at the Lotterywest Winners Room as soon as HQ opened on Monday morning after verifying her winning ticket the night before.

“I always play Saturday Lotto and check my numbers the next day in The Sunday Times,” she said.

“I checked and checked again because I thought there must be something funny going on with my eyes, but I definitely had six numbers.”

After sharing the happy news with her sister and niece, she then went to Galleria Lottery Centre, where she’d bought the lucky ticket.

“I’ve been buying my lottery tickets from Raymond for years,” she continued.

“He confirmed it and gave me a big hug and congratulations.”

The winner revealed her first purchase will be her own home, before donating a chunk of her windfall to a good cause.

“I’ve been renting the one I’m living in for a long time, and I’d like to buy it. Then I will buy my sister and niece a car each.

“As far as travel goes, I’d like to head up to Derby where I worked a long time ago to see friends.

“Many years ago, I was helped out by Vinnies, so I will also be making a donation to them.”

The retiree’s win marks a rare lottery double for Western Australia, with a single WA ticket securing the entire Saturday Lotto jackpot for the second time this year after a three-year drought.

Lotterywest spokesperson Jennie Fitzhardinge said it was very unusual for one player to take out the entire Division One prize pool.

“It is such a popular game, we usually have multiple winners each week across Australia,” Ms Fitzhardinge said.

Lotto players in WA will have the chance to win big in this Thursday’s Powerball, with a grand prize of $20 million.