A Perth man has revealed the moment he realised he had won millions after mistaking his Lotto win for just $920.

The Kenwick resident, who is in his 60s, said he missed one of the winning numbers in Saturday’s Superdraw when he first checked his ticket.

“I thought I had matched five numbers and won $920, which made me very happy,” he said.

“I returned to the newsagent’s at the end of the week and was shocked when the staff told me I had won $2.5 million.

The new millionaire said he plans to use his winnings to travel, help his children pay off their mortgages and buy a house by the sea.

Lotterywest spokeswoman Zoe Wender said the lucky local winner was the 38th division one winner in Western Australia this year, with the winners set to share a prize pool of $45 million.

“Western Australian players make Lotterywest grants possible, with last Saturday’s Superdraw alone raising over $3.3 million for our grants program,” Ms Wender said.