NEW YORK (Reuters) - Naomi Osaka received plenty of encouragement and advice from her mother Tamaki after her second round victory at the US Open on Wednesday (Sept 2), although it came in the form of emojis printed on a sheet of paper.

Shortly after defeating Italian Camila Giorgi 6-1, 6-2, 2018 champion Osaka was led to a courtside big screen to take a video call from her mother in Florida, which momentarily caught the 22-year-old off guard.

What followed was a slightly awkward exchange between mother and daughter amid audio connection issues, before Tamaki held up a sheet of paper with her message.

"I wasn't expecting it (the call) to happen. It was a surprise. Apparently my sister told my mum to do it," Osaka told reporters, before deciphering her mother's message.

"There were four lines. Thumbs up fire, which is like 'good job'. There was like a Twitter bird, whatever. She was saying 'don't go on social media, get some sleep'.

Then 'drink a lot of green juice, get some rest'. And 'I love you'."

"It was kind of a tech issue because normally I'm able to talk to her quite soundly. It would be kind of bad if all our conversations ended up like that. Definitely was a tech issue."

Karolina Muchova had also interacted with a special guest immediately after beating Venus Williams on Tuesday, after connecting virtually with actress Rebel Wilson.

"It was a bit odd because I remember I was watching Muchova playing Venus, and then I saw that she got a call ... from Rebel Wilson. I was like, 'Oh that's kind of cool'," Osaka added.

"Yeah, definitely wasn't expecting my mum to call today."