Rihanna thought Calvin Harris was "strange".
According to the 31-year-old DJ, the 'Rude Boy' singer saw him as a "kind of funny" guy making "cool" music when he joined her as a DJ support act on her 'Loud' tour in 2011.
He said: "She thought I was this kind of funny, this strange guy making cool music, or I guess what she thought was cool."
Calvin - who went on to produce the hit single 'We Found Love' with Rihanna later that year - was in awe of the star and couldn't believe it when she approached him to discuss a collaboration.
He said: "I'd never been around someone who was doing those shows so big, such a huge iconic presence. I kept my head down. Then I saw her at the last show and she told me she wanted to do a song like the one I was playing."
The 'Summer' hitmaker added that when the 27-year-old beauty agreed to credit his name on the record, it was a "mad dream come true".
He told The Sunday Times newspaper's Style magazine: "I was like, 'Look, this is my song. I've done everything. Would you consider putting my name on it?' And she did. Which is very gracious of her.
"It was just a mad dream come true. It made the sort of impact I hadn't even thought could be possible. It was crazy."