Florida (USA), March 23 -- Cameron Norrie and Katie Boulter were both knocked out in the third round of the Miami Open, ending British hopes in the singles here.

Norrie, 30, suffered a 7-5 6-7 (4-7) 6-4 defeat by 21-year-old Alex Michelsen of the United States in his first match of the tournament.

The 23rd seed, who replaced Jack Draper as British number one last week, lost a tight first set after Michelsen finally broke his serve with his sixth set point of the 12th game.

Norrie bounced back from a 3-0 deficit in the second set to force a tie-break which he won to forcea deciding set.

However, a break in the third game of the third set proved pivotal for Michelsen as he served his way into the last 16 on home soil.

British number thre...