Ilya Ivashka earned a meeting with Stefanos Tsitsipas at the Mallorca Championships, while Alex de Minaur got his Eastbourne International defence up and running with a straight-sets win on Monday.
A comfortable 6-4 6-1 victory over Emil Ruusuvuori sent Ivashka into the second round, where world number six Tsitsipas awaits after receiving a bye.
Mallorca third seed Denis Shapovalov will face Benjamin Bonzi who benefited as Alejandro Tabilo retired while trailing 6-3 4-2 to the Frenchman.
Roberto Bautista Agut overcame Taro Daniel 6-4 7-6 (7-4) to advance, while Antoine Bellier defeated Federico Delbonis 6-3 7-6 (8-6) and Feliciano Lopez fell to a 7-6 (7-3) 7-6 (7-3) loss to Tallon Griekspoor.
De Minaur took an hour and 23 minutes to get past Cristian Garin 6-3 6-3 for a strong start in his bid to retain the trophy in Eastbourne.
The Australian will either face compatriot James Duckworth or Lorenzo Sonego, who he defeated in the final last year, in round two.
Fifth seed Reilly Opelka fell to a 6-3 6-1 defeat against tournament debutant Maxime Cressy, while Alexander Bublik was three points away from losing to Frances Tiafoe before rallying back to win 5-7 7-6 (7-4) 6-0.
Bublik will face John Millman next after the Australian overcame Sebastian Korda 6-3 7-6 (7-5), while top seed Cameron Norrie awaits Brandon Nakashima and Diego Schwartzman is next in line for Jack Draper.
Korda withdrew from Wimbledon after the defeat to Millman, the 21-year-old American saying on Twitter he was suffering with "terrible shin splints and beaten up feet" and needed a rest.