Danielle Collins was greeted with loud boos as she stepped onto Rod Laver Arena for her third-round match against Madison Keys at the Australian Open. This reaction was expected after her behavior during her second-round match.

Danielle Collins of the U.S. reacts after defeating Destanee Aiava of Australia in their second ... (AP Photo/Manish Swarup, File) Novak Djokovic of Serbia gestures as he leaves Rod Laver Arena after retiring in his semifinal match against against ...

Lest we forget, this year’s Australian Open has reminded us of those unwritten rules.

The Australian Open crowd made sure to let Danielle Collins that they haven't forgotten what happened two days earlier as they treated the American with a round of loud boos as soon as she came out on Rod Laver Arena for her third-round match. On Thursday, the American overcame Australian qualifier Destanee Aiava in three sets.

American tennis star, Danielle Collins, was heavily booed onto the court at the Australian Open for her third round match against Madison Keys.

Just days after the polarising American taunted the crowd at Melbourne Park after beating local favourite Destanee Aiava ... crowd filtered back into Rod Laver Arena after watching men's top ...

Count Novak Djokovic as being in Danielle Collins' corner. He thinks her response to booing fans at the Australian Open was absolutely fine — which should come as no surprise, given the way Djokovic gets into back-and-forths with hecklers at his matches, including Friday night at Rod Laver Arena.

Danielle Collins said she was proud of herself and did not care what people thought after being booed in and out of the arena in losing 6-4, 6-4 to fellow American Madison Keys at the Australian Open on Saturday.

The Australian Open, the first Grand Slam of the year, ends on Sunday when defending champion Jannik Sinner faces Alexander Zverev for the men's title.

The Australian Open, the first Grand Slam of the year, ended Sunday with defending champion Jannik Sinner beating Alexander Zverev for the men's title. Let’s look back at five memorable storylines from the past two weeks in Melbourne:

Record crowds roamed Melbourne Park, new stars emerged, and old ones wound back the clock. Revellers had fun at the party court, but the same conduct was not welcomed by the players as it bled into the big matches.

Novak Djokovic climbed one place up to No.6 in the ATP rankings. Paula Badosa returned to the top 10 while lucky loser Eva Lys made her debut in the top 100 of the WTA rankings after advancing to the fourth round at Melbourne Park.