Alexander Zverev took a break in the fifth set to apply a medical spray to his legs, visibly struggling in the final stage of his epic clash with Rafael Nadal.
While players taking a brief break mid-match to treat ailments is nothing new, the 19-year-old's tactic left John Fitzgerald annoyed.
"I always think this should not be allowed, Jim," Fitzgerald said. "I always think it is a one on
one warrior against warrior and if you run out of gazette at the end, whether you are 19 or 39, that's part of the one on one competition."
"Yes, it is a hot debate, whether athletes can be treated," Jim Courier replied. "They can't be treated for injuries in the same way as if they had hurt their ankle or something. He can't take an injury time out in this situation. He's hurting."
Rafael Nadal finally took the win over Zverev late in the fifth set, forcing the exciting teenager out of the open - but that's far from the last we'll see of the young German.
There's a lot to like about the 19-year-old, sporting a powerful backhand and strong offensive play which sent Nadal around the court.
As impressive as he was, Nadal was simply too good towards the end, beating the young gun with experience and class.
The 30-year-old was in high praise of the youngster, calling him "the future of the sport" after the match.
DASHA'S WARDROBE SLIP-UP
Daria Gavrilova may want to converse with opponents before she next walks out on the court. The Aussie star's wardrobe selection caught the attention of fans before the start of her third round clash with Timea Bacsinszky, clearly wearing the same outfit as her Swiss opponent.
The awkward moment mirrored Channel Nine reporters Julie Snook and Amber Sherlock's awkward confrontation earlier in the month when an argument took place before the nightly news bulletin over matching outfits.
Gavrilova's slip-up became an instant talking point on Twitter with fans cheekily comparing it to the hilarious television encounter.
After a number of ups and downs, Daria Gavrilova progressed through to the fourth round for the second year in a row with a exhilarating win.
The 22-year-old looked shaky in the middle stages of her third round clash with Timea Bacsinszky, but she was able to pull through with a loud crowd behind her at Melbourne Park to seal the victory over her older opponent 6-3 5-7 6-4.
"I don't know (what to say). I'm just exhausted. I'm happy," she said after the match.
Gavrilova was elated after the win, dancing her way through the tunnel before meeting her boyfriend.
CROATIAN'S 19-YEAR FIRST
Mirjana Lucic-Baroni has continued her unlikely run at the Australian Open with a 3-6, 6-2, 6-3 win over Maria Sakkari of Greece to advance to the Round of 16. Before this week, the 34-year-old Lucic-Baroni hadn't won a match at Melbourne Park since her debut at the tournament in 1998. The 19-year gap in between match wins at a Grand Slam tournament broke the record set by Kimiko Date-Krumm, who went 17 years between match wins at Wimbledon.
Lucic-Baroni was a former tennis prodigy who reached the semi-finals of Wimbledon in 1999 as a 17-year-old and captured the Australian Open doubles title a year before that with Martina Hingis.
She next plays American Jennifer Brady, a qualifier ranked No. 116, for a chance to reach her first Grand Slam quarterfinal since her run at the All England Club 17 years ago.
- AP