Juan Martin del Potro booked a spot in the Delray Beach Open quarter-finals, while Nick Kyrgios failed to do so on Thursday.
Del Potro, playing his first tournament since October after a knee injury, broke once in each set to beat Reilly Opelka 6-4 6-4 in the second round.
The Argentine top seed, champion at the ATP 250 event in 2011, next faces Mackenzie McDonald, who overcame Guillermo Garcia-Lopez 7-5 6-4.
However, Kyrgios bowed out with a 6-2 3-6 6-3 loss to Radu Albot, who will meet Steve Johnson after the fourth seed's 7-5 7-5 victory over Paolo Lorenzi.
@RaduAlbot is into the #DBOpen quarter-finals after upsetting Nick Kyrgios 6-2, 3-6, 6-3 in R2.
— Delray Beach Open (@DelrayBeachOpen) February 21, 2019
: Andrew Patron/CameraSport pic.twitter.com/qWBWjxn4ZQ
At the Rio Open, the last of the remaining seeds – Joao Sousa – departed to leave the field wide open.
Sousa was beaten by qualifier Casper Ruud 6-3 3-6 6-4 in the second round to become the last of the eight seeds to exit.
.@CasperRuud98 alcança novamente a fase de quartas do #RioOpen com a vitória sobre João Sousa, 6/3 3/6 6/4. O sérvio Lesle Djere será o seu próximo oponente. pic.twitter.com/kZ7X3L6jY3
— Rio Open (@RioOpenOficial) February 21, 2019
Ruud will face Laslo Djere, who was too good for Taro Daniel 6-4 6-2 to add to his upset win over Dominic Thiem.
Pablo Cuevas and Albert Ramos-Vinolas will also meet after wins over Juan Ignacio Londero and Federico Delbonis respectively.