Having battled and overcome cancer last year, American Vicky Duval is just happy to grab any time on court she can.

The 20-year-old Haiti-born world no.656 gratefully accepted one unlikely opportunity yesterday at the mixed team Hopman Cup in Perth when Serena Williams was struck down with inflammation of the knee.

As first reserve, Duval was delighted to fill in for her revered compatriot, even if she struggled to a 6-4 6-1 loss to Elina Svitolina, of Ukraine.

The Eastern Europeans won the tie after Alexandr Dolgopolov beat Jack Sock 6-4 6-2 but a beaming Duval recovered to score a rare win by teaming up with Sock to take the doubles 6-2 6-3 and said the experience had been a good one.

“It was amazing. I was kind of nervous because I was filling in big shoes. But I had a really fun time today,” Duval said.

The American is expected to revert back to the sidelines for her country’s next tie tonight against Australia Gold with Williams’s knee expected to be up to the task.

Duval, previously tutored by legendary coach Nick Bollettieri, was diagnosed with Hodgkin’s lymphoma ahead of Wimbledon in 2014.

Other result: Great Britain bt France 2-1.