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.
Pironkova, who last played at Wimbledon in 2017, beat Alize Cornet 6-4 6-7 (5-7) 6-3 to set up a last-eight tie with Serena Williams.
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.