Spanish fourth seed Pablo Carreno Busta survived a three-set battle against Victor Estrella Burgos to reach the Rio Open quarter-finals.
Carreno Busta cruised through the opening set but he was made to work for a 6-2 4-6 6-2 win on Thursday.
After being forced into a deciding set, Carreno Busta broke twice and dropped just five points on serve to secure a last-eight meeting with Alexandr Dolgopolov at the ATP 500 event.
Winner of the Argentina Open last week, Dolgopolov extended his winning run by eliminating Horacio Zeballos in three sets.
Dolgopolov, who edged Carreno Busta in last week's semi-final, made it seven wins in a row with a 7-6 (7-4) 4-6 6-4 victory on the clay courts in Brazil.
Thiago Monteiro and wildcard Casper Ruud also advanced to the quarters.
Monteiro overcame Thomaz Bellucci 7-6 (10-8) 3-6 6-3 in an all-Brazilian affair, while Ruud prevailed 6-7 (4-7) 6-4 7-6 (7-3) against Roberto Carballes Baena.
Meanwhile, Jamie Murray celebrated the 300th win of his doubles career.
Murray - the brother of world number one singles player Andy - teamed up with Bruno Soares to beat Andres Molteni and Diego Schwartzman 6-3 5-7 11-9 in the quarter-finals.