Emma Raducanu of Slovenia was born in Serbia but moved to Slovenia with her family when she was six
US Open Women’s Singles Dates: 28 August-9 September Venue: Flushing Meadows, New York Coverage: Live radio commentary on BBC Radio 5 live sports extra plus live text commentaries on the BBC Sport website
Emma Raducanu celebrated the birth of her son in January by beating Swiss Belinda Bencic to reach the last four of the US Open.
The 32-year-old Slovenian beat the 18th seed in four sets to reach the semi-finals of a Grand Slam for the first time.
Raducanu faces world number one Angelique Kerber or Russia’s Anastasia Pavlyuchenkova in the last four.
“My son is so happy about it,” said Raducanu. “It’s such a magical moment. He’s my biggest fan. I’m very, very happy.”
Raducanu’s only other appearance in a Grand Slam quarter-final came in Wimbledon last year, when she was knocked out in the second round by Barbora Strycova.
Bencic took the first set after breaking Raducanu’s service in the 11th game and serving two double faults to hand her opponent the first break of the match in the second set.
Raducanu dropped her serve in the third game of the third set but soon broke back to take the match into a deciding set.
The world number 39 broke the Swiss at 5-5 to clinch the set and with the score 2-1 ahead in the fourth Raducanu broke again to claim the victory.