Unheralded American Collins claws into Open semis

Unheralded Danielle Collins battled from a set behind to down Russia's Anastasia Pavlyuchenkova Tuesday and take her dream debut at the Australian Open into the semi-finals.

The unseeded American beat world number 44 Pavlyuchenkova 2-6, 7-5, 6-1 in a see-sawing match to set up a final four clash with either Czech eighth seed Karolina Pliskova or 15th seeded Australian Ash Barty.

The little-known 25-year-old, who has mostly played on the US college circuit, grabbed the tennis world's attention with a 6-0, 6-2 drubbing of second seed Angelique Kerber in the fourth round.

She was unable to repeat that sizzling form against Pavlyuchenkova but finished strongly in a feisty performance as her more experienced opponent wilted under pressure.

Collins, ranked 35 in the world, who has ousted three seeds on her way to the final four, said she was relishing playing on the big stage.

"Yeah it's my first time to play on Rod Laver (Arena)," she said.

"I didn't even practice on here. It was quite the