Fabio Fognini crashed out of the Cordoba Open in the second round on a mixed day for the seeds in Argentina.
There were two seeds to progress in Diego Schwartzman and Guido Pella, who will do battle in the last eight.
Schwartzman overcame qualifier Alessandro Giannessi 6-7 (4-7) 6-3 6-0 and Pella was too good for Albert Ramos-Vinolas 6-4 7-6 (7-4).
Fognini, the top seed at the ATP 250 event, had won his previous eight meetings with Aljaz Bedene, but his unbeaten record was ended on Thursday.
The Italian suffered a 6-1 6-4 defeat to Bedene, who was clinical, converting six of his eight break points.
Bedene will face Pablo Cuevas in the quarter-finals after the Uruguayan eliminated sixth seed Malek Jaziri 7-6 (7-5) 6-2.
Italian second seed Marco Cecchinato also made a second-round exit, going down to Jaume Munar 6-3 3-6 6-1.
Munar will meet Federico Delbonis, who battled past Roberto Carballes Baena 6-7 (3-7) 6-2 6-2.