Alexandr Dolgopolov became the latest seed to fall at the Ecuador Open, while Alejandro Falla enjoyed a win.
Dolgopolov, the fifth seed from Ukraine, suffered a surprise 3-6 7-6 (7-4) 6-3 loss to American Rajeev Ram in the first round on Tuesday.
He joined fellow seeds Horacio Zeballos and Thiago Monteiro, who departed a day earlier, in making an early exit on the clay in Quito.
Awaiting Ram in the second round is Nicolas Kicker, who won an all-Argentine clash against Guido Andreozzi 4-6 6-3 6-4.
Qualifier Falla claimed his first ATP World Tour main-draw win since the same ATP 250 event a year ago.
The Colombian had few problems getting past Italian Alessandro Giannessi 6-4 6-3.
The eighth-seeded Renzo Olivo battled into the second round, overcoming wildcard Emilio Gomez 5-7 6-2 7-6 (7-5).
Australian Matthew Ebden battled past Agustin Velotti 2-6 6-4 6-3, Roberto Carballes Baena cruised past Rogerio Dutra Silva 6-3 6-1 and Joao Souza fell to qualifier Federico Gaio 5-7 6-4 7-5.