Australian Open: Four talking points

Jo-Wilfried Tsonga was challenged by more than just Kei Nishikori at the Australian Open as Serena Williams revealed her love of Snapchat.

From Jo-Wilfried Tsonga's on-court frustration to Serena Williams' off-court snapchatting, it's been an eventful day at Melbourne Park

Here's our pick of the major talking points from the Australian Open. 

It's a serve man

Tsonga struggled to get into his straight-sets loss to Nishikori and encountered some challenging problems. Nishikori had a second serve called out in the second game of the third set, only for that decision to be overruled by the chair umpire.

Tsonga walked to the deuce court awaiting the next point before being told the point was being replayed, leading to his desire to challenge the call.

"It's too late, Jo. It's too late," the chair umpire responded. "I didn’t hear it. What it's too late? It's a serve, man. Whatever, it's a serve. I can challenge whenever I want."

Not so, it seems.

He may not have been the victor today but >#Tsonga outsmarted >#Nishikori with this >@CPAAustralia Shot of the Day >https://t.co/NGpFxIEdX8

— Australian Open (@AustralianOpen) >January 24, 2016

Snaptchatting Serena 

She may be 34, but Serena Williams is still happy to keep up when it comes to social media.

After poor phone service let her down in Melbourne, the 21-time grand slam champion was unable to share a sword she found at the botanical gardens.

"I know I definitely felt [too old for Snap Chat] a few months ago, but I don't know," Williams said after beating Margarita Gasparyan.

"Now it's just become part of my life."

Another farewell for Hewitt

His singles career may have finished earlier in the week, but Australian veteran Lleyton Hewitt was given another farewell on Sunday. The two-time grand slam champion bowed out of the doubles with Sam Groth after a loss to Vasek Pospisil and Jack Sock.

There was more medical drama as well, with play delayed on Margaret Court Arena as a spectator required treatment.

Hewitt was, predictably, given a standing ovation as he left.

The champ's final match is over! Thanks >#Hewitt for the memories. >#AusOpen>https://t.co/unkAGDn13F

— Australian Open (@AustralianOpen) >January 24, 2016

Watch and learn for Bencic

Swiss teenager Belinda Bencic fought hard in a straight-sets loss to Maria Sharapova on Rod Laver Arena.

But her loss and Williams' win over Gasparyan set up a rematch of last year's final between the American and Sharapova in the quarter-finals.

One keen viewer will be the 18-year-old.

"Yeah, I'm definitely gonna be watching and learning," Bencic said.