Serena Williams knocks out world's number 1, Simona Halep, to reach her 12th Australian Open quarterfinal

Serena Williams has beat world's number 1 Simona Halep to reach the quarter-finals of the 2019 Australian Open.

Serena Williams, 37, sat out last year's Australian Open after giving birth to her daughter months earlier and suffering health complications. Since returning to the tour, Williams has reached the past two Grand Slam finals, losing both.

On Monday, the mother-of-one outlasted Simona Halep at Melbourne Park and won the fourth round match with a 6-1 4-6 6-4 victory.

Speaking on court, Williams said:

It was a really intense match, some incredible points. I love playing tennis, I love this court and it's really cool to be back out here playing.

I really needed to elevate my game and there's a reason why. She's a great player. I had to just play a little bit like I knew I could and I did, and I think hopefully that was the difference.

I'm such a fighter, I never give up. There's definitely something that's innate.

Serena will now make her way through to the quarter-final where she will meet Czech Karolina Pliskova.