Rafael Nadal moved into the Cincinnati Open quarter-finals with victory over fellow Spaniard Albert Ramos.
Both players were wearing black ribbons on their shirts in memory of the victims of the attacks that took place in Barcelona and Cambrils on Thursday.
Nadal, 31, won 7-6 (7-1) 6-2 to set up a quarter-final tie with Australia's Nick Kyrgrios.
Kyrgrios earlier beat Croatia's Ivo Karlovic 4-6 7-6 (8-6) 6-3.
Kyrgrios and Nadal will play their quarter-final match later on Friday (not before 00:00 BST on Saturday), because of the rain delays that affected Thursday's schedule.
Roger Federer's withdrawal from the tournament means Nadal will return to world number one for the first time since July 2014, taking over from Andy Murray who is also injured.