After her first round scare against Urszula Radwanska, Ivanovic was always in control against Wozniak, requiring little over an hour to wrap up a 64 62 victory. There was also little sign of the hip injury that bothered her against Radwanska.
"I mean it's better than it was - I had a lot of treatment and now have to do more recovery work for tomorrow - so I'm happy about that," Ivanovic said.
"It was a little bit of a strange game tonight. It's always strange playing someone for the first time and I didn't know much about her. She served really well and was getting a lot of first serves in, but I'm really happy to win in two sets and finish on a good note."
A bumper crowd crammed inside Club Sonoma's Cancha Central for Thursday's evening session and another full house is expected for Ivanovic's quarterfinal with Magdalena Rybarikova.
"It's my first quarterfinal here, so I'm excited," Ivanovic added. "It's really nice to play the night session and as the match progressed the stadium filled up - I really enjoyed playing in front of such a great and knowledgeable crowd."
Earlier in the day, there were wins for No.8 seed Monica Puig and the tournament's surprise package, Julia Boserup.
Puig arrived in México on the back of an up and down start to the year, but she has found the fast conditions in Monterrey to her liking and booked her place in the last eight with a 64 62 win over Nicole Gibbs.
"I think everything was pretty much working for me today," Puig said. "I was focusing mainly on what I've been working on with my coach and really just trying to keep as disciplined as I could.
"I haven't really had a great time since Wimbledon and have had a lot of ups and downs so it feels good to really blossom in this tournament and get to the quarterfinals. It means a lot because it's one of my first tournaments with my new coach and I'll try and go as far as I possibly can."