(CNN) Sofia Kenin's bid to defend her Australian Open title ended in disappointment on Thursday after she was knocked out of the tournament by world No. 65 Kaia Kanepi.
The American, who was moved to tears in her post-match press conference, looked way off her best and was beaten in straight sets 6-3 6-2 in just over an hour.
The 22-year-old Kenin had admitted to struggling with the pressure that comes with being champion and it showed -- she made 22 unforced errors against the experienced Kanepi, who dominated throughout with her aggression.
"I obviously felt like I couldn't find my rhythm. I was obviously too nervous," said Kenin, who praised Kanepi's performance.
"I'm not there 100% physically or mentally," added Kenin. "My game, everything, just feels really off. Obviously, it's not good. I just couldn't really handle the pressure. I'm not obviously used to this."
Despite a breakthrough season last year -- winning in Melbourne and reaching the final of the French Open -- nerves have been an issue for Kenin.
Even after playing well in her first-round victory, she said she struggled to manage her emotions on court.
Kenin's exit comes just days after French player Gael Monfils was also visibly emotional after being knocked out of the tournament. He too said he struggled with outside pressure and poor form coming into this tournament after such a difficult year.
If Kenin struggled with the weight of expectation on her, that shouldn't take anything away from Estonian Kanepi, who hit 22 winners and was thoroughly deserving of victory. She will now face Croatia's Donna Vekic in the third round.
"I served really well today, I think this helped a lot," said the 35-year-old Kanepi. "My game plan was to play aggressive as I usually do."
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Elsewhere, world No. 1 Ashleigh Barty progressed into the next round after beating fellow Australian Daria Gavrilova 6-1 7-6 (9-7).
Barty, who spent almost a year off the tour amid the pandemic, had won her first-round tie without dropping a single game but was given a much sterner test on Thursday.
After breezing through the opening set, Australian Barty was forced into a nail-biting tie-break to settle the contest.
"I think it's just trying to be the best I can be every day, whatever that level is," Barty said after the match.
"Just making sure that I apply myself the best that I can so that regardless of the result I can walk off the court with my head held high.
"Obviously having 12 months off is a little bit rusty, but certainly happy how I've been able to fight through the last couple of weeks."