[7] The same year he won the Homburg Cup by defeating the three-times defending champion and Germany's top player Otto Froitzheim.

[9] In September 1910 he won the singles title at the Montreux Tournament after defeating R. Norris Williams in the final in five sets.

[9] In the South of France Championships he and Max Decugis lost the doubles final to Tony Wilding and Josiah Ritchie.

[19] Heinrich's brother, Robert Kleinschroth,[20][21] also competed on the amateur tour, reaching the semi-finals of the World Hard Court Championships in 1912.

[17] He was a Juris Doctor, a degree he earned at the Ludwig Maximilian University of Munich and used that title later on and registered as such for tournaments.