Australian Open: Kanepi stuns holder Kenin

Reigning champion Sofia Kenin crashed out of the Australian Open in the second round on Thursday, slumping to a 6-3, 6-2 defeat at the hands of world No. 65 Kaia Kanepi on Margaret Court Arena.

The 22-year-old, who followed her Grand Slam breakthrough at Melbourne Park last year with a run to the final at the French Open, sprayed 22 unforced errors in the 64-minute contest against the experienced Estonian.

Kenin has been reduced to tears on court on several occasions since she came out of quarantine in Melbourne and admitted she has been struggling to contain her nerves at the prospect of defending the title.

Kanepi, who reached the final of the Gippsland Trophy warm-up tournament last week, was just the sort of hardened veteran who would look to exploit any mental frailties in her opponent.

The Estonian played a solid, if unspectacular, match, breaking Kenin for 3-1 in the opening set and never looking back after fending off three break points in the next game.

"I served really well today, I think this helped a lot," the 35-year-old said.

"My gameplan was to play aggressive as I usually do."

Kenin slammed her racket into the ground in frustration after losing the first set but never looked anything like the player who beat Garbine Muguruza in last year's final.

Kanepi kept up the pressure in the second set, in which Kenin failed to muster up a single break point, and the Estonian sealed her victory in emphatic style with her 10th ace.

Watched by her coach father Alex, Kenin gave a quick wave to the sparse crowd as she walked off court with her head bowed, her title defence over.

Next up for Kanepi is a third-round tie against Croatian Donna Vekic, who beat Argentine Nadia Podoroska in her second round match on Thursday.