Diego Schwartzman felt he played "an almost perfect match" to overcome Pedro Martinez in straight sets and reach the quarter-finals of the Rio Open.
The third seed advanced with a 6-1 6-1 victory, though that does not quite tell the whole story as the second game of the first set lasted a mammoth 24 minutes and 40 seconds.
Martinez saved eight break points in that lengthy game before finally being outdone by Schwartzman, who will now face another Spaniard in Pablo Andujar.
Incredibly, Martinez won 31 points in the first set but just one game.
"It was unbelievable," Schwartzman said. "This was probably the longest game in the history of the tournament
"I don't remember anything like this before. I played an almost perfect match, I played against an opponent that had as much confidence as me."
Andujar beat Albert Ramos-Vinolas 7-5 5-7 6-3, while fourth seed Pablo Carreno-Busta lost 5-7 6-4 6-3 to Fabio Fognini in the shock of the day.
Federico Coria awaits Fognini after following up his surprise win over defending champion Cristian Garin with a 7-6 (7-2) 4-6 6-4 victory against Fernando Verdasco.
At the Delray Beach Open, top seed Cameron Norrie beat Oscar Otte 6-3 7-5 and will face Sebastian Korda, who saw off Andreas Seppi 7-5 6-3, for a place in the semi-finals.
Tommy Paul and Stefan Kozlov are also through to the final eight in Florida after beating Denis Istomin and Steve Johnson respectively in straight sets.