Bulgaria's Tsvetana Pironkova described her return to tennis as "unreal" after she reached the US Open quarter-finals for the first time following a three-year hiatus from the sport.

The 32-year-old considered not returning to the tour following the birth of her son in March 2018.

"It's absolutely unreal," she said.

"I really can't believe it. I was so exhausted by the end of the match I really didn't believe I had it in me. I kept fighting and it obviously paid off."

Pironkova, who was 131st in the world when she last played in 2017, decided to return in March this year after new ranking protection rules allowed players going on maternity leave to enter 12 events on their previous ranking.

A fourth-round match against France's world number 56 Cornet was a comparatively easy draw for Pironkova, who has already beaten 10th seed Garbine Muguruza and 18th seed Donna Vekic at this year's US Open.

Known as a grass-court specialist, the 2010 Wimbledon semi-finalist had only made it to the US Open fourth round once before - in 2012.

Pironkova did not drop a set en route to the fourth round and looked set to continue that form as a late break in the first gave her the lead.

In the second, she served for the match twice but Cornet broke back both times and the Bulgarian was taken to a tie-break, which she lost.

As both players began to tire, they exchanged breaks early in the decider but a sublime backhand passing shot but Pironkova 5-3 up and she held serve to set up a quarter-final against six-time US Open champion Williams.

When asked afterwards whether it was hard spending so much time away from her son, Pironkova held back tears.

"I haven't seen him in two weeks," she said. "It's very tough and it gets tougher every day.

"I know he's watching me and I know he's proud of me. It's worth it."