British number three Alex Bogdanovic was knocked out by Spain's Feliciano Lopez in the first qualifying round for the Miami Masters in Florida.
Bogdanovic also lost in qualifying last week in Indian Wells
World number 150 Bogdanvic made a real fight of it against a player ranked 66 places above him but went down 6-2 3-6 7-6 (7-3) in just over two hours.
Lopez, who made the world's top 20 last year, had to save 12 break points against the British 22-year-old.
Bogdanovic also lost in qualifying at Indian Wells last week.