Petzer was born in Parys and initially attended high school in Kroonstad, where he earned a call-up to represent the Griffons at the Under-16 Grant Khomo Week in 2012.
He joined the Western Province academy after school,[2] but left Cape Town after just one year to return to the Griffons.
[4] In the second half of the season, Petzer joined the Free State Cheetahs, and he made his Currie Cup debut for the team in a match against the Golden Lions.
[5] A few weeks later, injuries to a number of Cheetahs' Pro14 fly-halves — with Niel Marais, Fred Zeilinga, Ernst Stapelberg and Ryno Eksteen all injured — Petzer was called up into the squad and he started their second ever match, an 18–51 defeat to Irish side Munster in Limerick, with Petzer scoring eight of his side's points.
He spent one season there before joining Major League Rugby side Glendale Raptors.