Cameron Norrie marked his first appearance on the British grass courts since last year's Wimbledon semi-finals with a confident win at Queen's.
Norrie, seeded fifth, beat Serbia's Miomir Kecmanovic 6-4 7-6 (7-5) on the first day of the competition.
Compatriot Ryan Peniston, who reached the quarter-finals last year, earned an impressive win on his return after being given a wildcard.
The world number 265 shocked 37th-ranked Frenchman Ugo Humbert 6-4 6-2.
Dan Evans, Britain's second highest-ranked man, will aim to secure a hat-trick of home victories later on Monday when he plays American Sebastian Korda.