The couple, from Warsaw, were reportedly visiting relatives in Watford but wanted to sample London's nightlife before returning home to Poland.
They had pre-booked tickets after seeing an advert for the London nightclub in a Polish newspaper, it was reported.
DJ Hansen, 35, who was playing at the club, said he initially thought they were lost when he spotted them slowly making their way down the stairs.
He told the Evening Standard: "I was downstairs just opening and I saw her on her crutches going slowly down the stairs.
"I thought they were lost. They didn't speak English really.
"I thought they were maybe relatives of someone from the club, but then I spoke to the people on the door and they said they had tickets.
"I ran down to welcome them to the club, I said 'it's amazing you're here' and gave them a drink.
"They had two tequila shots and she gave me a high five.
"I was desperate to find someone who could speak to them and find out their story."
He managed to find a Polish speaker, who discovered the woman was visiting her daughter and often enjoyed Saturday night clubbing back in Poland.
When he asked who bought the tickets, the elderly woman grinned and said she had.
The couple told Hansen they planned to get the Tube back to Watford at 6am.
However the DJ, real name Jacob Husley, claimed he told the pair the club would pay for a taxi home and they could drink for free, before escorting them to the VIP area.
He told the Standard: "I took them upstairs to the balcony and brought them some tea - because they wanted to have tea.
"They were really sweet, they were on the balcony with their hands together ballroom dancing."
But later, he went to check on them, and they had vanished.
He looked down and saw them partying to techno music on the dance floor.
"They wanted to join in the party," he told the newspaper. "They weren't interested in upstairs.
"She was really slow so he went a bit more into the dance floor and got some dances with the young girls"
The couple got a taxi home at 5am after dancing the night away.