Juan Martin del Porto fought back to reach the second round of the Cincinnati Masters after beating Czech Republican Tomas Berdych 2-6 7-6 (7-1) 6-0 in almost two hours.
The Argentine with the victory means he will play Mitchell Krueger in the next round.
Elsewhere, there were wins for Austrian Dominic Thiem who saw off Fabio Fognini 7-6 (7-5) 6-4 and American John Isner who beat fellow American Tommy Paul 6-3 6-3 to reach the next round.
Thiem with the win sets up a clash with either French Adrian Mannarino or American Sam Querrey while Isner will battle either German Alexander Zverev or fellow French Frances Tiafoe in the second round.
In other games, Austrian Nick Kyrgios saw off David Goffin from Belgium 6-2 6-3 to set up a meeting with Alexandr Dolgopolov of Ukraine in the second round.
The winner of the clash between Nick Krygios and Dolgopolov will take on Ivo Karlovic in the third round after the Croat saw off Jo-Wilfried Tsonga 6-4 7-6 (11-9).
Canadian Milos Raonic ranked 10th had to withdraw from the tournament after suffering a wrist injury.