Gilles Muller advanced at Hall of Fame Tennis Championships but fellow seeds Ryan Harrison and Alex de Minaur departed in the opening round.
Muller will retire at the end of the ATP Tour season but the 35-year-old Luxembourgish veteran showed he is not a spent force just yet after seeing off Marcos Baghdatis 7-6 (7-5) 6-3 in Newport.
Seeded sixth, Muller – a Wimbledon and US Open quarter-finalist – saved three of four break points faced and converted a pair of his own to progress to the second round on the grass in Rhode Island on Tuesday.
The 2016 Newport runner-up will face Marcel Granollers in the next round after the Spaniard defeated qualifier JC Aragone 7-6 (7-6) 6-0.
Harrison and De Minaur, meanwhile, fell at the first hurdle at the ATP 250 tournament.
American fifth seed Harrison was trailing Nicholas Mahut 2-0 in the second set having dropped the opener 6-2 before retiring.
Australian youngster De Minaur – the seventh seed – lost 6-7 (2-7) 7-6 (7-3) 7-5 against big-serving Croatian and 2016 champion Ivo Karlovic.
Bernard Tomic was beaten 6-3 1-6 6-2 by Dudi Sela, Ramkumar Ramanathan accounted for Victor Estrella Burgos 6-4 6-1, Sergiy Stakhovsky went down 6-4 3-6 6-3 to Jason Jung, while wildcard Christian Harrison outlasted Alex Bolt 6-3 4-6 7-5.
