The American won an astonishing 23 Grand Slam titles throughout her career with only Margaret Court owning more.
But back in 2010 the 43-year-old was in search of her 12th major when she faced Justin Henin at Melbourne Park.
Serena Williams dominated plenty of her Grand Slam finals but this was one she had to win the hard way, and she did just that.
Serena Williams says what gave her extra motivation to win the 2010 Australian Open final
Williams breezed throughout her first four rounds at the Australian Open, before needing three sets to win her quarter-final against Victoria Azarenka.
She then came through two tiebreaks to beat Lia Na in the semi-finals, before facing an old foe in Justin Henin for the title.
Williams was struggling with injury and after losing the second set, she was losing motivation and struggling to fight through the pain. That was until a fan yelled something at her, which sparked a fire in Williams that ultimately drove her to victory.
“I remember when I was playing Justine Henin in the final and I had to find motivation to be resilient,” Williams said in a video posted on Instagram.
“I hurt my knee, I had two bone bruises, one in the left, one in the right, I could not move. I was in so much physical pain and nobody knew, and I just felt like giving up.
“I just needed some motivation. I just felt like ‘gosh, this is not going well, I’m exhausted, my knees are killing me and I need to get surgery after this, but I’m just going to figure this out and be done with it.’
“I needed motivation and this guy in the stands said ‘hey Serena, I knew you weren’t that good’. I looked at him and I was like ‘I’m about to show you what’s good, I’m about to show you resilience.’
“I don’t know how many games I lost after that but it wasn’t that many, and I was like ‘that was what I needed.”
