The man and his girlfriend escaped unharmed as he asked for her hand in marriage outside the burning flat.
The fire service described the chain of events in a series of tweets, adding: "As a bonus, she said YES!"
But they also warned that candles should never be left unattended.
"As romantic as they are, and as much as we all love 'em, candles can be SO dangerous."
"Please, please extinguish them properly when you've done, don't put them near flammable items, like curtains and don't leave 100s of tea lights unattended."
The owner of the newsagents told the Sheffield Star that the man proposed outside while the fire was still raging.
"He didn't get on his knees and she gave him a kiss. He had to make her happy after all that somehow."