Wednesday's match was interrupted by an advertising hoarding falling on spectators during the opening set.
A section of the hoarding came crashing down from the upper tier onto spectators below, forcing the chair umpire to stop play before Zverev immediately procured an ice pack for an elderly woman who'd been injured.
The players waited patiently while tournament organisers scrambled to provide medical assistance.
Organisers said the 62-year-old did not suffer any major injuries and was able to leave the stadium after the initial shock, but she was taken to hospital as a precaution.
They added that drumming against the boards may have caused the screws to come loose.
"There has never been anything like this in our 32-year tournament history. We deeply regret the incident," tournament director Ralf Weber said in a statement.
On court, Zverev finished the match with 23 winners in the 79-minute contest where Giron struggled to match the power of the German's first serve and had no answer when his opponent's returns found all corners of the court.
World No.3 Zverev, still nursing the disappointment of Sunday's Stuttgart Open final defeat by Taylor Fritz, showed no mercy with the home fans firmly behind the towering second seed who has finished runner-up twice in Halle.
"I hope the lady is okay. Something like that should of course not happen," Zverev said.
"Of course, I am happy with the way I played. But the most important thing is that everyone here goes home healthy and happy.
"It was a great match for me, I thought it was quite high level. Maybe he wanted to play a bit better than he did, but all in all I felt like I didn't let him play that well, which was important for me."
Earlier, eighth seed Karen Khachanov dispatched Belgium's Zizou Bergs 7-5 6-3 despite a nasty fall on the grass.
