Magnus Gustafsson defeated Ivan Lendl 6-4 7-5 in the Munich semi-final on clay. The upset overturned the form book — Ivan Lendl came in leading the head-to-head 1–0. Magnus Gustafsson claimed a first win over Ivan Lendl in two meetings, levelling the head-to-head at 1–1.
Gustafsson M. took it in straight sets.
Clay: Gustafsson M. leads 1–0 · Hard: Lendl I. leads 1–0
Magnus Gustafsson beat Ivan Lendl 6-4 7-5. Umpiry, "Magnus Gustafsson vs Ivan Lendl — Munich Semi-final", https://umpiry.com/match/1991-04-29/gustafsson-vs-lendl-munich-sf?utm_source=cite (as of 29 April 1991).