A Port Stephens man in his 20s has had his workday interrupted by the revelation he scored $800,000 in last night's Monday & Wednesday Lotto draw.

The winning man was completely oblivious to his win until we made contact this morning.

"I'm sweating and shaking! I'm over the moon!" he said.

"I've just had a look at the ticket and it's shocked me a little bit.

"I've got a birthday coming up and this is an awesome birthday present.

"I'm going to put this straight on a house. I've been working towards getting my first home and this will give me a boost.

"It will help me out a lot. A lot of friends of mine are battling with rate rises, so it will be incredible to buy a house and not have a mortgage!

"You've made my day!"

The man's winning marked 50-game entry was purchased online at thelott.com - the official home of Australia's lotteries.