"I just don't know what to say, it was really close to a perfect moment," Vetter told World Athletics.
But after that goal, Poland took control of the game for the rest of the first half, and their domination paid off when Kamil Glik equalized just before half-time.
Chen Siyan (70) and Yin Xiaowen (71) were the top amateurs at three-under par, tied for equal sixth with Miranda Wang Xinying (69) at seven strokes back.
Rodriguinho had given Bahia the lead at Internacional's Beira-Rio stadium when he cut onto his left foot and slotted a low shot into the bottom left corner.
"Serena is Serena," Sakkari said after advancing earlier Saturday by beating 19-year-old American Amanda Anisimova 6-3, 6-1. "You have to come up with some great tennis. Otherwise there is no chance against her."
The 165-yard 16th hole proved the difference as Zhang three-putted on the way to a bogey four. Yin answered with a birdie two for a two-shot swing and a one stroke lead she would never relinquish in her bogey-free round.
"It's going to be one of the young guys, I think, if you count Dominic Thiem as a young guy, as well. He obviously has a chance to win. Now I think it is the time where it gets really interesting. We'll see where we go from here." Enditem
"It's good that I managed to win in three sets and with a day off and just a three-setter to play, I'm feeling good," said last year's runner-up Medvedev.
Pepe has made 99 appearances for Gremio and scored 21 goals since making his professional debut in 2017.
Some of the country's top athletes serving sanctions for the doping offices includes 2008 Beijing Olympics 1,500m champion Asbel Kiprop, 2016 Rio Olympics women's marathon champion Jemimah Sumgong, and former three-time Boston Marathon champion Rita Jeptoo, among others.
Patrick Bezerra equalized eight minutes later with a header following Thiago Galhardo's cross.