Ania Magennis might be too young to recall her brush with tennis great Serena Williams, but the memory will be etched in her parents’ minds for ever.

Esperance mother Marta Magennis and her husband Conor took a break from yesterday’s Germany versus Spain match to feed one-month-old Ania when they saw Williams practising on the outside courts.

Ms Magennis was among dozens of surprised fans to witness the star sharpen her skill against her US partner Frances Tiafoe.

As Williams left RAC Arena practice court, the new mother jagged a selfie with the player holding Ania.

“Everyone was taking photos with her and I said ‘can my baby get a photo with you’ and I handed her my baby,” Ms Magennis said. “I knew she would because she’s a mother, too.”

Avid tennis fan Ms Magennis said she had long admired Williams for her ability to endure anything and for coming back after becoming a parent.

Bibra Lake’s Chemutai Glasheen, who brought her daughter and niece to see Williams practise, said the American was her favourite player.

“There’s something about her — she is compelling and she has got grit,” Ms Glasheen said.

“I have seen her play in Perth before but this is the closest I have got.”

Stefano Ghedian, of Jandakot, said yesterday was the first time he had seen Williams in the flesh, despite attending Wimbledon several times.

“I have seen all the other players except for her — it’s great,” he said.

Jackson Withford, 24, and his mother Vicki Withford came from Sydney for the Hopman Cup and were delighted to watch Williams practise.

“I have never seen her play before so it is pretty cool to see her in person,” he said.

Williams practised for at least an hour on the courts outside the arena but stopped several times to nurse a sore left ankle.

Her playing partner Tiafoe looked strong.

Greek player Maria Sakkari, 23, can’t wait for her first clash with her childhood hero Williams at RAC Arena today.

“It’s a dream coming true,” Sakkari said. “I grew up watching her, she was one of my heroes. Her power obviously and she has done great things for our sport.”

World No. 41 Sakkari will be hoping that she has already played and won a match against Katie Boulter on Saturday will be an advantage.

“Maybe, but with her you have no advantages,” Sakkari said. “She’s the GOAT (greatest of all time) so it’s going to be tough.”

Rising men’s star Stefanos Tsitsipas is also looking forward to getting on court with Williams in the mixed doubles.

“Playing against her will be a big lesson for me,” the world No. 15 said. “I’ll try to play my best game, because it would be great to get a win against her. It’s going to be good preparation for the Australian Open.”