Ronaldo was the talisman of that United team, and scored in the 1-1 draw with Chelsea in Moscow, which they eventually won on penalties.
The Portuguese star was the designated free-kick taker, but Hargreaves was also often seen over the dead-ball.
Questioned as to how he came to share the duties with Ronaldo, Hargreaves told BeIN Sports: “Ask politely, like anything. But to be fair we used to practise all the time and he knew I could take them.”
Hargreaves explained how he would rarely be given an opportunity to show what he could do at Bayern Munich, but Ronaldo welcomed his talents.
“We used to practise all the time and Cristiano knew I could [score them] and I love that about him, he said.
“I remember we played, I’d scored a couple, and we practised before the Champions League final against Chelsea that year, he was on one side of the box and I was on the other.
“I hit nine out of ten into the top corner, Edwin [van der Sar] was in goal.
“And Edwin came to me and said, ‘Owen, if we get a free-kick in the Champions League final you’ve gotta take it’.
“I said, ‘I can’t take it off Cristiano, that’s Cristiano Ronaldo ‘.
“Anyway, we get to the dressing room, we’re warming up to go out on the pitch before we go out, nobody is around, Cristiano walks over and says, ‘Owen if we get a free-kick today it’s yours, I saw you practising’.
“And that’s who he was. Everybody thinks he’s like it’s all about him and an egomaniac. But if you’re good at something he’s the first one to see that.
“And that’s why I got to take a couple that year because he knew I might score. I admire that about him, I really do.”