World number five Alexander Zverev appears to have found form at the right time heading into the French Open.
A pair of seeds exited at the Geneva Open on Monday, while Grigor Dimitrov's match with Federico Delbonis was postponed.
World number one Novak Djokovic survived a brief scare to get past Federico Delbonis at the Miami Open.
Nick Kyrgios outlasted fifth seed John Millman 6-4 6-7 (1-7) 7-6 (7-3) in the opening round of the ATP 250 tournament on Monday.
Guido Pella set up an all-Argentine final with a three-set victory over Pablo Cuevas after Juan Ignacio Londero defeated Federico Delbonis.
Guido Pella beat Diego Schwartzman in an all-Argentine affair on the clay courts of the ATP 250 tournament in Cordoba on Friday.
Spanish veteran David Ferrer – a three-time winner and this year's seventh seed – was beaten 7-5 6-2 by Caser Ruud.
Juan Martin del Potro produced the greatest comeback in Davis Cup history on Sunday, according to victorious captain Daniel Orsanic.
World number six Marin Cilic needed five sets in the Davis Cup final opener to beat Federico Delbonis and put Croatia 1-0 up on Argentina.