It was something Flipkens highlighted when she reflected afterwards that she found it difficult to adjust to playing someone of Ivanovic's level (Ivanovic is ranked No 16) as opposed to others she's faced this week.
"I didn't think I was playing bad,'' Flipkens said. "It was just Ana was playing amazing. I haven't played against a top-20 player since Venus at the US Open. It's a different kind of level playing against Ana than others ranked around 50.''
Williams might be ranked 47 but she's a seven-time grand slam champion and has beaten Ivanovic eight out of the nine times the pair have met. Ivanovic's only win came in the quarter-finals of the 2008 Australian Open when she finished runner-up to Maria Sharapova.
"I have struggled against both Serena and Venus in the past because they have a big serve and sometimes that's overwhelming to see that coming at you,'' Ivanovic said. "Over the years you get used to it a bit, you mature and handle the situations differently.
"There's no doubt it's going to be a very tough match and it's a matter of still doing the things I've been working on and trying to impose my game.''
Both players have errors in them but both have also improved as the week has progressed. The pair are the two biggest servers at the tournament _ Williams has registered one at 202kmh this week _ and they both go after their shots.
There are varying theories about whether it's an advantage or not for Williams to have had the day off.
"I feel like I have been playing every day and I have a rhythm,'' Ivanovic said. "Venus had today off, which can be good because she's more rested, but sometimes it means you lose that feeling of playing a match every day.''
It also means Ivanovic will have one more day of her morning ritual in Auckland. The 26-year-old is superstitious _ her most obvious is her efforts to avoid stepping on white lines on court _ and she has eaten the same breakfast every morning this week.
"I said, 'one more day and then I can change my breakfast,'' the tournament's second seed admitted. "My dad is like, 'I don't understand how you can eat salmon for breakfast'. I have salmon and rice every morning and some eggs. It's quite weird. I really love fish and the salmon here just tastes amazing.''
Victory would be even more palatable and for Ivanovic it would be her first on tour since 2011. Williams hasn't won since 2012.
It's only hoped the match lives up to expectations.