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.