FRANKFURT, Germany (AP) Steve Darcis defeated Alexander Zverev 2-6, 6-4, 6-4, 7-6 (8) to send Belgium into the Davis Cup World Group quarterfinals with an unsurmountable 3-1 lead over Germany on Sunday.
With the tie already decided, Ruben Bemelmans beat Mischa Zverev 7-5, 6-1, giving Belgium a 4-1 upset victory - its first over Germany at the ninth attempt in the Davis Cup.
Darcis, the Belgian No. 1 in the absence of David Goffin, rallied after losing the first set of the decisive rubber and held his nerve when the 19-year-old Zverev saved three match points in the tiebreaker to win in just over three hours.
''That's why we love the Davis Cup as we have surprises and we had one today,'' the 58th-ranked Darcis said. ''The difference between us and them is that we are really a team. They have so many great players but we play with the heart, for our country and for the people here.''
Darcis was ranked lower than three players on the German team.
Zverev fired 21 aces, took the first set in under 30 minutes, and appeared to have everything under control until Darcis fought his way back midway through the second set.
Germany now faces another relegation playoff in September after its third straight first-round defeat.
''Somehow everything went wrong from the start,'' Germany team captain Michael Kohlmann said.
Darcis began his heroics by beating Philipp Kohlschreiber in the opening rubber.
''We need three miracles to get through this tie,'' Darcis said afterward.
Alexander Zverev defeated Arthur De Greef for Germany's only point on Friday, before losing with his brother Mischa to Ruben Bemelmans and Joris De Loore in Saturday's doubles.
Darcis did the rest.
''The whole weekend went badly for us somehow,'' Alexander Zverev said. ''We could have been leading 2-0 after the first day.''