American Danielle Collins continued her remarkable grand slam breakthrough by defeating Anastasia Pavlyuchenkova to reach her first semi-final at the Australian Open.

The 25-year-old arrived at Melbourne Park having never won a match in the main draw of a slam but recovered from a set down to win 2-6 7-5 6-1 in two hours and 16 minutes.

This was a meeting between two players looking to make the last four at a slam for the first time but it was Collins who swept through the third set, clinching her third match point when Pavlyuchenkova missed a forehand.

Collins' relatively late breakthrough can be mostly attributed to her taking the unusual path for a top female singles player of going to college in the United States.

Ranked outside the top 100 at the start of 2018, she finished it at 36 after a string of impressive performances, particularly in the spring, when she reached the fourth round in Indian Wells and then the semi-finals in Miami, beating Venus Williams.

Her scalps here have included Julia Goerges, Caroline Garcia and second seed Angelique Kerber, who she allowed just two games in the fourth round.

A proudly abrasive presence on court, Collins struggled in the first set, with Pavlyuchenkova able to dictate much of the play and feasting on her opponent's second serve.

Pavlyuchenkova, 27, was formerly the world number one junior and reached her first slam quarter-final way back in 2011, but injuries and fluctuations in form have taken their toll since and she won just two matches at the slams last season.

The powerful Russian found herself given much more of a challenge in the second set as Collins began to find her range, and the American moved into a 5-2 lead.

Pavlyuchenkova battled back to level at 5-5 but Collins converted her third break point at 6-5, letting out a scream of determination.

And from that point there was no looking back for the world number 35, who saw a match point come and go at 5-0 before taking her third opportunity in the next game.