(Photo credit: Geoff Burke-Imagn Images)Second-seeded Ben Shelton survived a stiff test from qualifier Martin Damm on Tuesday, winning an all-U.S. matchup 6-4, 4-6, 6-4 in the first round of the Mubadala DC Open in Washington. Shelton broke serve to end his first match since he took a marathon five-set loss against Finland’s Otto Virtanen in the opening round at Wimbledon. The other seeded U.S. player in action on Tuesday lost, as France’s Adrian Mannarino downed fifth-seeded Learner Tien 7-5, 6-4. Seventh-seeded Jakub Mensik of the Czech Republic emerged with a 6-2, 6-7 (5), 6-3 victory over U.S. qualifier Trevor Svajda. The other Tuesday winners were Poland’s Kamil Majchrzak, France’s Ugo Humbert, Australian qualifier Cruz Hewitt and the U.S. duo of Alex Michelsen and Brandon Nakashima.