Serena Williams labelled the Hopman Cup doubles contest that saw her go up against Roger Federer as the "match of my career".

Regarded by many as the best ever players in women's and men's tennis respectively, Williams and Federer went head to head in Perth on Tuesday as the American teamed up with Frances Tiafoe and the Swiss with Belinda Bencic in a mixed doubles match.

It was the combination of Federer and Bencic that prevailed but for Williams, who will move level with Margaret Court for the most women's singles Grand Slam titles if she wins her 24th at the Australian Open, which starts this month, the unique encounter was a career highlight.

"I was so excited, it was literally the match of my career," Williams said. "Just playing someone so great, someone that you admire so much and a match that actually means something. It's not often that happens.

Read: Federer gets bragging rights over Williams in hugely anticipated match

"Years and years of admiring him and just being level with him in the same point of our career and being the same age and it was really cool to actually play someone, still in their prime like me, both in our primes, this doesn't happen so it was really cool.

"It was definitely different. It wasn't as nerve-wracking as I just wanted to do really well but I think it was a little nerve-wracking because I didn't do as well. I am the one who has won those doubles Grand Slams but it looked like he was the one who won all those doubles Grand Slams today, but it was what it was.

"My first service game went well. You know it's fine but the most important thing is that this is all leading to the road to Australia, well to the Open, so it's good.

"I think what I remember most about it is that we both are kind of at the pinnacle of our careers, we are both still playing some of our best tennis and that's so special to be competing against each other. It's just not normal, men and women's tennis just don't compete against each other. It's just really great and special to go against the greatest."