Roger Federer barely raised a sweat as he accounted for Juan Ignacio Londero 6-3 6-4 in Cincinnati on Tuesday.
As five seeds fell at the Citi Open, Stefanos Tsitsipas and Nick Kyrgios were second-round winners.
Holger Rune defeated Fabian Marozsan 6-4, 6-4 on Tuesday evening. He'll face Argentinian qualifier Marco Trungelliti in the next round
Roberto Carballes Baena won against Roman Safiullin 5-7, 7-6 (3), 6-3 on Tuesday. He'll play the winner of the match between Kazakh qualifier Denis Yevseyev and Frenchman Alexandre Muller in the next round
Hubert Hurkacz won against Flavio Cobolli 7-5, 7-6 (2) on Monday evening and will play the winner of the match between Brazilian wildcard Joao Fonseca and Australian qualifier James Duckworth in the next round