The 31-year-old American arrived for the clash on Rod Laver Arena having not lost a set throughout the tournament, but wilted under the lights of the showcourt on Thursday before going down fighting 6-3, 7-6(7).
"I've been playing every match during the day. It's playing much hotter, much faster. Getting out there it was a nice night, cool, but very slow. It took me a while to get my feet under me," Pegula told reporters.
"My timing was really off for a while and it's hard against someone that hits as big as she does. She adapted quicker and was hitting that big, heavy ball at me ... I was making a lot of errors, not staying through my shots as well as I could have.
"Then I think I finally started to find my timing a bit and play a lot better. So the conditions for sure ... I was a little erratic in the beginning, overthinking it a little bit too and not just trusting the things that I had been doing as well."
Despite her maiden last-four appearance at Melbourne Park ending in disappointment, Pegula said she was in no doubt about her quality after reaching back-to-back Grand Slam semi-finals on hardcourts after her inspired run at last year's US Open.
"It's tough, I had an amazing tournament here," she said.
"I played some really good tennis, beat a lot of really good players, put up a fight tonight, but obviously I want to win the tournament. That always sucks when you don't.
"So though my experience over the last couple of years has made me feel a lot more comfortable at this stage. I've made two slam semi-finals back to back, I think that's really good, and put myself in these positions.
"I still feel like I'm getting better as a player. Honestly, it's hard to really knock ... I wanted to win the tournament and give myself a chance but at the same time, I've had some pretty amazing results over the last few years."
Pegula reached the final at Flushing Meadows in 2024, losing to Aryna Sabalenka.
"I think I'm a top player," she declared.
"On hardcourts, I'm maybe top three in the world. That's definitely a great achievement. The people who have stopped me the last couple of times went on to win the tournament or they're in the finals."