"I woke up in the morning and just felt this pain in my neck," the Spanish No.1 told reporters. "I went to the physio to get treatment and tried to play at 11:30, then had physio again and tried to play again at 2:15, and I just couldn't serve. I couldn't play like I wanted. So I had to pull out of this final.
"I'm really sorry. I love this tournament and I had a great week. I really tried today."
The fans still got a great show, though - Kim Clijsters, a four-time Grand Slam champion and former World No.1 who is now Tournament Director of the Premier-level stop, stepped in for an exhibition match with Petkovic, and she thrilled her home fans with some fierce hitting and a 5-3 victory.
The always-charismatic Petkovic won the crowd over in her post-match interview, though.
"I hope you don't take any offense Kim," she said, "but I'm glad you are done playing on tour."
Don't let the walkover in the final take anything away from Petkovic's triumph, either. She had to work very, very hard just to get to the final, including an absolute marathon in her second round match against Belgian wildcard Alison Van Uytvanck, saving eight match points and battling for three hours and 19 minutes - the longest match of the year so far - to earn a 6-7(7), 7-6(5), 6-2 victory.
And by virtue of her results in Antwerp, Petkovic will break back into the Top 10 this week, her 27th career week inside the elite. She spent her first 26 weeks there from August 8, 2011 and April 1, 2012 - she fell as low as No.192 in the time between due to a series back, ankle and knee injuries.
The Premier-level BNP Paribas Fortis Diamond Games is Petkovic's equal-biggest career title - she won her first Premier-level title at Charleston last year. The German has six WTA titles in total.
Petkovic spoke about the final walkover against Suárez Navarro in her post-match press conference.
"Right before we went on court I was warming up and they told me the news. At first I was very shocked because I didn't know anything about her physical pain and the blockage. But secondly I was sad. I really like Carla - she's a great person and always friendly and positive, and she has a tremendous amount of talent. Also, you can never really enjoy the win when you don't fight for it.
"So I'm happy I had a great week and I'm leaving as the champion, but definitely mixed emotions."