ATP roundup: Arthur Rinderknech upsets Denis Shapovalov in Stuttgart

Frenchman Arthur Rinderknech knocked off Canada's Denis Shapovalov 6-4, 2-6, 6-0 in Stuttgart on Tuesday in the first round of the BOSS Open at Stuttgart, Germany.

Shapovalov, seeded fifth in the event, was undone by nine double faults, while his opponent fired nine aces. Rinderknech committed just 18 unforced errors to Shapovalov's 28 while prevailing in 1 hour, 43 minutes.

The only seeded player to win on Tuesday was No. 7 American Alex Michelsen, who downed France's Gael Monfils 6-4, 4-6, 6-3.

Other winners were Germany's Justin Engel, Hungary's Marton Fucsovics, American Learner Tien and France's Quentin Halys, Pierre-Hugues Herbert and Corentin Moutet.

Libema Open

Americans Mackenzie McDonald and Reilly Opelka each earned three-set victories in 's-Hertogenbosch, Netherlands.

McDonald cruised past Italy's Mattia Bellucci 6-1, 6-7 (4), 6-3, while Opelka rallied to defeat the Netherlands' own Jesper de Jon 6-7 (5), 7-6 (5), 6-2.

Also on Tuesday, Finland's Otto Virtanen defeated Argentina's Tomas Martin Etcheverry 7-6 (6), 7-5, and in a battle of Belgium, Zizou Bergs downed Alexander Blockx 6-3, 1-6, 7-6 (3).