Britain's Cameron Norrie, Liam Broady and Katie Boulter are through the first round of qualifying at the Miami Open.
World number 105 Norrie was 6-1 2-0 up when his American opponent Stefan Kozlov, ranked 167th, had to retire.
Broady, the British number four, moved easily past Henri Laaksonen of Switzerland, winning 6-2 6-4 against the world number 132.
Katie Boulter, the British number four, beat American world number 100 Taylor Townsend 7-6 (7-1) 6-2.
Elsewhere in the women's draw, Naomi Broady, the sister of Liam, was frustrated by France's Oceane Dodin, losing 4-6 7-5 6-3.
British number two Heather Watson plays her first-round match at 18:00 GMT on Tuesday against Brazilian Beatriz Haddad Maia, who is ranked 64th in the world.
Defending champion and British number one Johanna Konta has a bye to the second round.
Men's British number one Kyle Edmund also has a bye to the second round as he goes in search of his first win since the Australian Open.
Meanwhile, Canadian former Wimbledon finalist Eugenie Bouchard beat American wildcard and world number 357 Allie Kiick 6-2 6-2 in first-round qualifying.
Bouchard, now ranked 114th, was playing her first match since a first-round loss at Indian Wells two weeks ago.