There was no place to hide for Alexander Zverev, who was left ashen-faced when he learned during an on-court interview that it was his father's birthday.
Zverev had just beaten British No. 1 Cameron Norrie in a helter-skelter of a match that took four hours and nine minutes to decide and reach the quarterfinal. The German narrowly prevailed in a 10-point fifth-set tiebreak. It was the third time at this year's Australian Open that he was taken the distance.
Only one of Zverev's four matches on his path to the last eight was in straight sets. He needed four sets to beat countryman Dominik Koepfer in the first round and withstood a spirited challenge from Slovakian qualifier Lukas Klein in five sets.
Zverev will be keen to forget an embarrassing moment that happened in the aftermath of his win over Norrie when the on-court interviewer reminded him it was his father's birthday and that Zverev had just gifted him the perfect present by winning the match.
Alexander Zverev Sr. was in the stands and has always been part of his son's coaching entourage since he began playing the sport. He turned 64 on Monday. Unbeknownst to him, young Zverev tried to cover his face in shame, but it was all in vain.
"I completely forgot, I'm very very sorry."
But Zverev redeemed himself when he chaired the birthday choir, singing in unison with those who gathered to watch the match outside Margaret Court to wish his dad a happy birthday, and all was certainly forgiven.
Zverev will look to extend his winning record in Wednesday's quarterfinal against World No. 2 Carlos Alcaraz. The sixth seed leads 4-3 in tour-level meetings, beating the Spaniard in three sets at the ATP Finals in Turin last November. The German has been to a semifinal of the Australian Open once in his career (2020).