(Photo credit: Jonathan Hui-Imagn Images)

Lucky loser Aleksandar Kovacevic rallied to stun No. 1 seed Felix Auger-Aliassime of Canada 4-6, 7-5, 6-4 at the Hamburg Open on Wednesday in Germany.

Kovacevic trailed 4-1 in the deciding set before winning five straight games to beat the fifth-ranked player in the world and become the first American to reach the Hamburg quarterfinals since Andre Agassi and Pete Sampras in 1995. No. 5 seed Karen Khachanov of Russia and No. 8 Frances Tiafoe were also upset. Khachanov's rally came up short in a 6-3, 3-6, 7-6 (3) loss to France's Ugo Humbert, while Tiafoe was tightly swept 7-6 (3), 7-6 (4) by Camilo Ugo Carabelli of Argentina.

No. 6 Tommy Paul joined Kovacevic as an American Hamburg quarterfinalist by rallying in the Wednesday resumption of his 6-7 (5), 7-6 (5), 7-6 (7) defeat of Argentina's Tomas Martin Etcheverry which took 3 hours, 33 minutes to complete. No. 3 Alex de Minaur of Australia beat Spain's Alejandro Davidovich Fokina 6-2, 4-6, 6-4. Peruvian qualifier Ignacio Buse beat Czech Jakub Mensik 6-0, 6-3 in a battle of unseeded competitors. In the final match of the day, No. 7 Italian Luciano Darderi swept Germany's Yannick Hanfmann 7-6 (7), 7-5.

Geneva Open

Unseeded Alexei Popyrin spoiled Taylor Fritz's Switzerland debut, knocking out the top seed 6-4, 6-4 to reach the quarterfinals.

Fritz, who was playing his first match since March, had seven aces and no double faults, but couldn't force a single break-point opportunity against the Australian, who had a clutch break in each set. No. 3 seed Cameron Norrie of Great Britain lost 6-4, 6-4 to unseeded Argentinian Mariano Navone in what was otherwise a chaos-free day of action.

In other competition, No. 2 Alexander Bublik of Kazakhstan swept Lithuanian qualifier Edas Butvilas 6-4, 6-3, No. 4 Learner Tien came through in the clutch in a 7-6 (4), 7-6 (2) victory over Greece's Stefano Tsitsipas and No. 5 Arthur Rinderknech of France surged past Serbia's Laslo Djere for a 4-6, 7-6 (4), 6-1 victory. No. 6 Casper Ruud of Norway swept Belgium's Raphael Collignon 7-6 (2), 6-2, Spanish eighth seed Jaume Munar disposed of Argentina's Francisco Comesana 6-4, 6-4 and Alex Michelsen beat Swiss wild card Stan Wawrinka 7-6 (1), 7-6 (4).--Field Level Media