High Quality Content by WIKIPEDIA articles! The 1989 Davis Cup was the 78th edition of the most important tournament between national teams in men`s tennis. Beginning with this year, teams advanced from Group I to the World Group Qualifying Round, where they played alongside first round losing teams from the World Group, rather than receive direct promotion. The tiebreak was also introduced into Davis Cup competition. A total of 79 nations participated in the tournament. In the final, West Germany defeated Sweden at the Schleyerhalle in Stuttgart, West Germany, on 15-17 December.