The two Australian-based movie stars have become good friends over the years and so playing rivals in the new movie musical was tough at times - because Jackman owes his pal so much.
He tells EW.com, ""We were good friends before. We knew each other a lot. And Russell has given me advice several times at key moments in my life that helped with my career. I also owe him because two of the biggest roles I've ever had in my life, he turned down - and suggested me for them.
""On X-Men, he was Bryan Singer's first choice for Wolverine, and he mentioned me also for Australia. He really is incredibly smart, and generous. It was a joy to work with him.""