Azarenka thriving at Australian Open after downing Ostapenko
The 34-year-old Belarusian is looking to match or better her performance in Melbourne last year, when she made the semi-finals, and moved a step closer by reaching the last 16.
She did so by beating the in-form Ostapenko 6-1, 7-5, winning the last five games to topple a player who surged back into the top 10 for the first time since 2018 after winning the lead-up Adelaide International.
"I don't really like to play against her. It's not like I'm looking forward to it because she's a tough player," said Azarenka, who won back-to-back Australian Opens in 2012 and 2013.
"I think I'm just ready to give whatever it takes. I'm going to stay out here as long as I need to be.
"I love a challenge, I love the challenge whenever something is difficult, I love to do that, that makes me excited. I think that brings out the best in me."
Playing at her 16th Australian Open and 63rd Grand Slam, the former world number one said she had always embraced pressure.
"How can you get to win titles without pressure, it's impossible," she said.
"So I feel like you just can't run away from it. You have to face it right in front of you. It's scary, it's difficult but it's something that you want to acknowledge and go through."
She will face Ukrainian qualifier Dayana Yastremska for a place in the quarter-finals.