During the 1926 season, Thevenow hit the first home run of his major league career on September 17 off Cincinnati Reds pitcher Jack Knight, an inside-the-park homer that was part of 10–1 win over fading Cincinnati; the Reds went on to lose seven of their last nine games down the stretch. Five days later, Thevenow would hit another inside-the-park home run, the second and final regular season home run of his career, as the Cardinals beat the Brooklyn Dodgers by a score of 15–7, putting the Cardinals  games ahead of the Reds for first place in the National League.
Thevenow's first major league home run occurred on September 17, 1926, off Cincinnati Reds pitcher Jack Knight, an inside-the-park homer that was part of a 10–1 win over struggling Cincinnati; the Reds then lost seven of their final nine games. Five days later, Thevenow hit another inside-the-park home run, securing his second and final regular season home run of his career, as the Cardinals defeated the Brooklyn Dodgers 15–7, taking the lead in the National League.