Azarenka was serving at 61 10 when, after being wrongfooted, she went down on the baseline screaming in pain, clutching her right leg - she ended up getting treated on court for a right knee injury.
"After the serve, it happened so quickly in a second that my leg kind of collapsed," Azarenka said. "It felt like my knee just turned to the other way, and it was just so nasty. I was in such shock. For two minutes I had such consistent pain that it just completely freaked me out. Because you never know - you're just down on the ground and you never know what happened. It was so quick and a huge shock.
"At that moment it's so shocking because you have no ground. You basically just fall. Your legs go one way and there's no balance or nothing. Nothing I could control in that moment, and that's scary."
After the timeout Azarenka was moving gingerly but she fought through it, trying to keep control of the rallies so she wouldn't have to run too much, and the No.2-seeded Belarusian would win, 61 62.
"At that moment I was just thinking I had to try to do something," Azarenka said. "I was concerned, and the physios were concerned. 'Can you go through, can you play on it?' And I had no idea until I went and tried. It felt really painful. One moment it was getting better, then it was inconsistent - but I just wanted to give everything I had on the court even though I knew it could get worse out there.
"So I really went for my shots - I felt like I had to be aggressive, to finish as quick as possible."
After the match, Azarenka had the injury assessed, but nothing final yet. "I still have to do some more check-ups to make sure," she said. "I will still have some tests today to cover every single possibility, but I still need to make the final assessments. It's good to have tomorrow so I can recover."
And at the end of the day, the effort Azarenka put forth after such a scary incident was admirable.
"I'm pretty proud of the way I programmed my mind and took it one at a time, because it's never easy. At one point I couldn't even see the ball - all I could think about was what happened. So that shock took a while for me to get over. But I'm really glad I could find that calmness in that critical moment."